How to use groovy to cleanup the properties teststep

I have read a lot in this forum and in other places to cleanup project/testsuite/testcase properties. I was looking for some groovy to cleanup the properties teststep with a script. There is a setting to clear all values when saving but I am searching for a script so that I can decide when to cleanup. The name of these teststeps very but it is always of type properties teststep.

Any idea?