diff --git a/test/distrib/cpp/run_distrib_test.sh b/test/distrib/cpp/run_distrib_test.sh
index 9c8da508334..6b2e043491f 100755
--- a/test/distrib/cpp/run_distrib_test.sh
+++ b/test/distrib/cpp/run_distrib_test.sh
@@ -33,7 +33,7 @@ set -ex
 git clone $EXTERNAL_GIT_ROOT
 cd grpc
 
-# clone submodules
+# clone gRPC submodules, use data from locally cloned submodules where possible
 git submodule | awk -v EXTERNAL_GIT_ROOT=$EXTERNAL_GIT_ROOT/ '{ system("git \
 submodule update --init --reference " EXTERNAL_GIT_ROOT$2 " " $2) }'
 
diff --git a/tools/dockerfile/grpc_check_generated_pb_files/check_pb_files.sh b/tools/dockerfile/grpc_check_generated_pb_files/check_pb_files.sh
index b112fb11bb6..4773a602a4c 100755
--- a/tools/dockerfile/grpc_check_generated_pb_files/check_pb_files.sh
+++ b/tools/dockerfile/grpc_check_generated_pb_files/check_pb_files.sh
@@ -35,7 +35,7 @@ git clone /var/local/jenkins/grpc /var/local/git/grpc
 
 cd /var/local/git/grpc
 
-# clone gRPC submodules
+# clone gRPC submodules, use data from locally cloned submodules where possible
 git submodule | awk '{ system("git submodule update --init --reference \
 ./../../jenkins/grpc/" $2 " " $2) }'
 
diff --git a/tools/dockerfile/interoptest/grpc_interop_csharp/build_interop.sh b/tools/dockerfile/interoptest/grpc_interop_csharp/build_interop.sh
index 50378032dba..6a0b2ef0605 100755
--- a/tools/dockerfile/interoptest/grpc_interop_csharp/build_interop.sh
+++ b/tools/dockerfile/interoptest/grpc_interop_csharp/build_interop.sh
@@ -39,7 +39,7 @@ cp -r /var/local/jenkins/service_account $HOME || true
 
 cd /var/local/git/grpc
 
-# clone gRPC submodules
+# clone gRPC submodules, use data from locally cloned submodules where possible
 git submodule | awk '{ system("git submodule update --init --reference \
 ./../../jenkins/grpc/" $2 " " $2) }'
 
diff --git a/tools/dockerfile/interoptest/grpc_interop_csharpcoreclr/build_interop.sh b/tools/dockerfile/interoptest/grpc_interop_csharpcoreclr/build_interop.sh
index c4092743034..c2bb64e84b5 100755
--- a/tools/dockerfile/interoptest/grpc_interop_csharpcoreclr/build_interop.sh
+++ b/tools/dockerfile/interoptest/grpc_interop_csharpcoreclr/build_interop.sh
@@ -39,7 +39,7 @@ cp -r /var/local/jenkins/service_account $HOME || true
 
 cd /var/local/git/grpc
 
-# clone gRPC submodules
+# clone gRPC submodules, use data from locally cloned submodules where possible
 git submodule | awk '{ system("git submodule update --init --reference \
 ./../../jenkins/grpc/" $2 " " $2) }'
 
diff --git a/tools/dockerfile/interoptest/grpc_interop_cxx/build_interop.sh b/tools/dockerfile/interoptest/grpc_interop_cxx/build_interop.sh
index 6f8b41241f9..47380c8a125 100755
--- a/tools/dockerfile/interoptest/grpc_interop_cxx/build_interop.sh
+++ b/tools/dockerfile/interoptest/grpc_interop_cxx/build_interop.sh
@@ -39,7 +39,7 @@ cp -r /var/local/jenkins/service_account $HOME || true
 
 cd /var/local/git/grpc
 
-# clone gRPC submodules
+# clone gRPC submodules, use data from locally cloned submodules where possible
 git submodule | awk '{ system("git submodule update --init --reference \
 ./../../jenkins/grpc/" $2 " " $2) }'
 
diff --git a/tools/dockerfile/interoptest/grpc_interop_http2/build_interop.sh b/tools/dockerfile/interoptest/grpc_interop_http2/build_interop.sh
index 9c99bf56f54..3adc8394902 100755
--- a/tools/dockerfile/interoptest/grpc_interop_http2/build_interop.sh
+++ b/tools/dockerfile/interoptest/grpc_interop_http2/build_interop.sh
@@ -34,7 +34,7 @@ set -e
 mkdir -p /var/local/git
 git clone /var/local/jenkins/grpc /var/local/git/grpc
 
-# clone gRPC submodules
+# clone gRPC submodules, use data from locally cloned submodules where possible
 (cd /var/local/git/grpc/ && exec git submodule | awk '{ system("git submodule \
 update --init --reference ./../../jenkins/grpc/" $2 " " $2) }')
 
diff --git a/tools/dockerfile/interoptest/grpc_interop_node/build_interop.sh b/tools/dockerfile/interoptest/grpc_interop_node/build_interop.sh
index c82972d34e8..4b73bb56f80 100755
--- a/tools/dockerfile/interoptest/grpc_interop_node/build_interop.sh
+++ b/tools/dockerfile/interoptest/grpc_interop_node/build_interop.sh
@@ -39,7 +39,7 @@ cp -r /var/local/jenkins/service_account $HOME || true
 
 cd /var/local/git/grpc
 
-# clone gRPC submodules
+# clone gRPC submodules, use data from locally cloned submodules where possible
 git submodule | awk '{ system("git submodule update --init --reference \
 ./../../jenkins/grpc/" $2 " " $2) }'
 
diff --git a/tools/dockerfile/interoptest/grpc_interop_php/build_interop.sh b/tools/dockerfile/interoptest/grpc_interop_php/build_interop.sh
index fcdb28dcdf3..48a6444821a 100755
--- a/tools/dockerfile/interoptest/grpc_interop_php/build_interop.sh
+++ b/tools/dockerfile/interoptest/grpc_interop_php/build_interop.sh
@@ -39,7 +39,7 @@ cp -r /var/local/jenkins/service_account $HOME || true
 
 cd /var/local/git/grpc
 
-# clone gRPC submodules
+# clone gRPC submodules, use data from locally cloned submodules where possible
 git submodule | awk '{ system("git submodule update --init --reference \
 ./../../jenkins/grpc/" $2 " " $2) }'
 
diff --git a/tools/dockerfile/interoptest/grpc_interop_php7/build_interop.sh b/tools/dockerfile/interoptest/grpc_interop_php7/build_interop.sh
index 865802e30b6..c2348f4f666 100755
--- a/tools/dockerfile/interoptest/grpc_interop_php7/build_interop.sh
+++ b/tools/dockerfile/interoptest/grpc_interop_php7/build_interop.sh
@@ -39,7 +39,7 @@ cp -r /var/local/jenkins/service_account $HOME || true
 
 cd /var/local/git/grpc
 
-# clone gRPC submodules
+# clone gRPC submodules, use data from locally cloned submodules where possible
 git submodule | awk '{ system("git submodule update --init --reference \
 ./../../jenkins/grpc/" $2 " " $2) }'
 
diff --git a/tools/dockerfile/interoptest/grpc_interop_python/build_interop.sh b/tools/dockerfile/interoptest/grpc_interop_python/build_interop.sh
index 917477c8471..e85153f51a0 100755
--- a/tools/dockerfile/interoptest/grpc_interop_python/build_interop.sh
+++ b/tools/dockerfile/interoptest/grpc_interop_python/build_interop.sh
@@ -39,7 +39,7 @@ cp -r /var/local/jenkins/service_account $HOME || true
 
 cd /var/local/git/grpc
 
-# clone gRPC submodules
+# clone gRPC submodules, use data from locally cloned submodules where possible
 git submodule | awk '{ system("git submodule update --init --reference \
 ./../../jenkins/grpc/" $2 " " $2) }'
 
diff --git a/tools/dockerfile/interoptest/grpc_interop_ruby/build_interop.sh b/tools/dockerfile/interoptest/grpc_interop_ruby/build_interop.sh
index 449a21ff650..e5edb5335cb 100755
--- a/tools/dockerfile/interoptest/grpc_interop_ruby/build_interop.sh
+++ b/tools/dockerfile/interoptest/grpc_interop_ruby/build_interop.sh
@@ -39,7 +39,7 @@ cp -r /var/local/jenkins/service_account $HOME || true
 
 cd /var/local/git/grpc
 
-# clone gRPC submodules
+# clone gRPC submodules, use data from locally cloned submodules where possible
 git submodule | awk '{ system("git submodule update --init --reference \
 ./../../jenkins/grpc/" $2 " " $2) }'
 
diff --git a/tools/dockerfile/stress_test/grpc_interop_stress_csharp/build_interop_stress.sh b/tools/dockerfile/stress_test/grpc_interop_stress_csharp/build_interop_stress.sh
index e25783a0b3b..84920860803 100755
--- a/tools/dockerfile/stress_test/grpc_interop_stress_csharp/build_interop_stress.sh
+++ b/tools/dockerfile/stress_test/grpc_interop_stress_csharp/build_interop_stress.sh
@@ -39,7 +39,7 @@ cp -r /var/local/jenkins/service_account $HOME || true
 
 cd /var/local/git/grpc
 
-# clone gRPC submodules
+# clone gRPC submodules, use data from locally cloned submodules where possible
 git submodule | awk '{ system("git submodule update --init --reference \
 ./../../jenkins/grpc/" $2 " " $2) }'
 
diff --git a/tools/dockerfile/stress_test/grpc_interop_stress_cxx/build_interop_stress.sh b/tools/dockerfile/stress_test/grpc_interop_stress_cxx/build_interop_stress.sh
index d223653f92f..9ab7aa07274 100755
--- a/tools/dockerfile/stress_test/grpc_interop_stress_cxx/build_interop_stress.sh
+++ b/tools/dockerfile/stress_test/grpc_interop_stress_cxx/build_interop_stress.sh
@@ -39,7 +39,7 @@ cp -r /var/local/jenkins/service_account $HOME || true
 
 cd /var/local/git/grpc
 
-# clone gRPC submodules
+# clone gRPC submodules, use data from locally cloned submodules where possible
 git submodule | awk '{ system("git submodule update --init --reference \
 ./../../jenkins/grpc/" $2 " " $2) }'
 
diff --git a/tools/dockerfile/stress_test/grpc_interop_stress_go/build_interop_stress.sh b/tools/dockerfile/stress_test/grpc_interop_stress_go/build_interop_stress.sh
index a1d243d411d..de8430d6778 100755
--- a/tools/dockerfile/stress_test/grpc_interop_stress_go/build_interop_stress.sh
+++ b/tools/dockerfile/stress_test/grpc_interop_stress_go/build_interop_stress.sh
@@ -40,7 +40,7 @@ git clone --recursive /var/local/jenkins/grpc-go src/google.golang.org/grpc
 # grpc/tools/gcp/stress_tests
 git clone /var/local/jenkins/grpc /var/local/git/grpc
 
-# clone gRPC submodules
+# clone gRPC submodules, use data from locally cloned submodules where possible
 (cd /var/local/git/grpc/ && exec git submodule | awk '{ system("git submodule \
 update --init --reference ./../../jenkins/grpc/" $2 " " $2) }')
 
diff --git a/tools/dockerfile/stress_test/grpc_interop_stress_java/build_interop_stress.sh b/tools/dockerfile/stress_test/grpc_interop_stress_java/build_interop_stress.sh
index 4400e74be54..ffffea18d21 100755
--- a/tools/dockerfile/stress_test/grpc_interop_stress_java/build_interop_stress.sh
+++ b/tools/dockerfile/stress_test/grpc_interop_stress_java/build_interop_stress.sh
@@ -38,7 +38,7 @@ git clone --recursive --depth 1 /var/local/jenkins/grpc-java /var/local/git/grpc
 # grpc repo (for metrics client and for the stress test wrapper scripts)
 git clone /var/local/jenkins/grpc /var/local/git/grpc
 
-# clone gRPC submodules
+# clone gRPC submodules, use data from locally cloned submodules where possible
 (cd /var/local/git/grpc/ && exec git submodule | awk '{ system("git submodule \
 update --init --reference ./../../jenkins/grpc/" $2 " " $2) }')
 
diff --git a/tools/dockerfile/stress_test/grpc_interop_stress_node/build_interop_stress.sh b/tools/dockerfile/stress_test/grpc_interop_stress_node/build_interop_stress.sh
index c82972d34e8..4b73bb56f80 100755
--- a/tools/dockerfile/stress_test/grpc_interop_stress_node/build_interop_stress.sh
+++ b/tools/dockerfile/stress_test/grpc_interop_stress_node/build_interop_stress.sh
@@ -39,7 +39,7 @@ cp -r /var/local/jenkins/service_account $HOME || true
 
 cd /var/local/git/grpc
 
-# clone gRPC submodules
+# clone gRPC submodules, use data from locally cloned submodules where possible
 git submodule | awk '{ system("git submodule update --init --reference \
 ./../../jenkins/grpc/" $2 " " $2) }'
 
diff --git a/tools/dockerfile/stress_test/grpc_interop_stress_php/build_interop_stress.sh b/tools/dockerfile/stress_test/grpc_interop_stress_php/build_interop_stress.sh
index d1ac59fd917..78bf32ce519 100755
--- a/tools/dockerfile/stress_test/grpc_interop_stress_php/build_interop_stress.sh
+++ b/tools/dockerfile/stress_test/grpc_interop_stress_php/build_interop_stress.sh
@@ -39,7 +39,7 @@ cp -r /var/local/jenkins/service_account $HOME || true
 
 cd /var/local/git/grpc
 
-# clone gRPC submodules
+# clone gRPC submodules, use data from locally cloned submodules where possible
 git submodule | awk '{ system("git submodule update --init --reference \
 ./../../jenkins/grpc/" $2 " " $2) }'
 
diff --git a/tools/dockerfile/stress_test/grpc_interop_stress_python/build_interop_stress.sh b/tools/dockerfile/stress_test/grpc_interop_stress_python/build_interop_stress.sh
index ee70c1f3a9a..3f85a868032 100755
--- a/tools/dockerfile/stress_test/grpc_interop_stress_python/build_interop_stress.sh
+++ b/tools/dockerfile/stress_test/grpc_interop_stress_python/build_interop_stress.sh
@@ -39,7 +39,7 @@ cp -r /var/local/jenkins/service_account $HOME || true
 
 cd /var/local/git/grpc
 
-# clone gRPC submodules
+# clone gRPC submodules, use data from locally cloned submodules where possible
 git submodule | awk '{ system("git submodule update --init --reference \
 ./../../jenkins/grpc/" $2 " " $2) }'
 
diff --git a/tools/dockerfile/stress_test/grpc_interop_stress_ruby/build_interop_stress.sh b/tools/dockerfile/stress_test/grpc_interop_stress_ruby/build_interop_stress.sh
index 5e47bafe859..09b6fb1e117 100755
--- a/tools/dockerfile/stress_test/grpc_interop_stress_ruby/build_interop_stress.sh
+++ b/tools/dockerfile/stress_test/grpc_interop_stress_ruby/build_interop_stress.sh
@@ -39,7 +39,7 @@ cp -r /var/local/jenkins/service_account $HOME || true
 
 cd /var/local/git/grpc
 
-# clone gRPC submodules
+# clone gRPC submodules, use data from locally cloned submodules where possible
 git submodule | awk '{ system("git submodule update --init --reference \
 ./../../jenkins/grpc/" $2 " " $2) }'
 
diff --git a/tools/run_tests/dockerize/docker_run.sh b/tools/run_tests/dockerize/docker_run.sh
index 791ed6d7b00..e57ceaf0ac8 100755
--- a/tools/run_tests/dockerize/docker_run.sh
+++ b/tools/run_tests/dockerize/docker_run.sh
@@ -37,7 +37,7 @@ if [ "$RELATIVE_COPY_PATH" == "" ]
 then
   mkdir -p /var/local/git
   git clone "$EXTERNAL_GIT_ROOT" /var/local/git/grpc
-  # clone gRPC submodules
+  # clone gRPC submodules, use data from locally cloned submodules where possible
   (cd var/local/git/grpc && exec git submodule | awk -v \
   EXTERNAL_GIT_ROOT=$EXTERNAL_GIT_ROOT/ '{ system("git submodule update --init \
   --reference " EXTERNAL_GIT_ROOT$2 " " $2) }')
diff --git a/tools/run_tests/dockerize/docker_run_tests.sh b/tools/run_tests/dockerize/docker_run_tests.sh
index ee4c1a5f05d..a1e94b29527 100755
--- a/tools/run_tests/dockerize/docker_run_tests.sh
+++ b/tools/run_tests/dockerize/docker_run_tests.sh
@@ -44,7 +44,7 @@ chown $(whoami) $XDG_CACHE_HOME
 mkdir -p /var/local/git
 git clone /var/local/jenkins/grpc /var/local/git/grpc
 
-# clone gRPC submodules
+# clone gRPC submodules, use data from locally cloned submodules where possible
 (cd /var/local/git/grpc/ && exec git submodule | awk '{ system("git submodule \
 update --init --reference ./../../jenkins/grpc/" $2 " " $2) }')