Hi there,
I am running MODx Revolution 2.0.4-pl2 and the purge deleted docs has broken all of a sudden... Was working a few weeks ago, it removes the docs from the menu but they reappear when the menu loads again.
I’d suggest upgrading to 2.0.8 or waiting until 2.1-pl is available (hopefully, next week).
You could also try deleting all the files in the core/cache directory.