To delete all .svn folders from SVN working directory for releasing folder from SVN just do this simple steps.
Create new file in /usr/local/bin with name svnrm with following content
#!/bin/sh find . -name .svn -print0 | xargs -0 rm -rf
Save it. From now on you can execute svnrm command in your working directory and it will delete all .svn folders at once.