How to best clean up @script directories from using Pipeline

[Leon Poon]

We are starting to use the Pipeline plugin, and we noticed that it creates additional "<job name>@script" directories that do not get deleted automatically even when the jobs are deleted. What is the best approach to clean up these directories? I tried adding the following "step ([$class: 'WsCleanup'])" as the last step in Jenkinsfile, but the @script directories are still not cleaned up. Any recommendations?