This plugin will help you prevent bad words in confession and comment, you can replace bad words with another string you want. You can also use this plugin for on-page SEO, replace keyword with link you want. Very useful.
Replace bad words in comment
Replace bad words in confession
Replace bad words after post or only when display (Option)
Custom replacement (In other scrip/plugin, bad words have to be replaced with * but with this plugin, you can replace your own funny words)