PeepSo WordFilter Addon GPL Overview:

Set the filter to work on posts, comments, or both.
Automatically filters out unwanted phrases in PeepSo messages and chat.

Easy To Change, Easy To RollBack

The plugin masks forbidden words and phrases, but it does not interfere with the original posts. You’ll still be able to show a word or a phrase you’ve previously blocked, or change the rendering of the filter on the front end.

Changing the rendering from ##### to *****, for example, is as simple as changing the setting on the back end. To remove a word from the banned list, simply delete it from the back-end settings.