diff --git a/first-network/byfn.sh b/first-network/byfn.sh
index 0e68afc4..a10e0a36 100755
--- a/first-network/byfn.sh
+++ b/first-network/byfn.sh
@@ -87,7 +87,7 @@ function askProceed () {
 # Obtain CONTAINER_IDS and remove them
 # TODO Might want to make this optional - could clear other containers
 function clearContainers () {
-  CONTAINER_IDS=$(docker ps -aq)
+  CONTAINER_IDS=$(docker ps -a |awk '($2 ~ /dev-peer.*.mycc.*/) {print $1}')
   if [ -z "$CONTAINER_IDS" -o "$CONTAINER_IDS" == " " ]; then
     echo "---- No containers available for deletion ----"
   else
@@ -99,7 +99,7 @@ function clearContainers () {
 # specifically the following images are often left behind:
 # TODO list generated image naming patterns
 function removeUnwantedImages() {
-  DOCKER_IMAGE_IDS=$(docker images | grep "dev\|none\|test-vp\|peer[0-9]-" | awk '{print $3}')
+  DOCKER_IMAGE_IDS=$(docker images|awk '($1 ~ /dev-peer.*.mycc.*/) {print $3}')
   if [ -z "$DOCKER_IMAGE_IDS" -o "$DOCKER_IMAGE_IDS" == " " ]; then
     echo "---- No images available for deletion ----"
   else