Set up Replace Word run after page load, but alter it before display to user's browser.
ProfanityBlocker is a cloud based word filter service that scans for profane (swearing/abusive) words - giving you control of allowed text on your sit
Replace word by another word in post, page, or comment. And... bbPress
Update or clean the contents of your site, by filtering or replacing words and phrases in your posts, pages, excerpts, titles and comments.
Versatile Censor Tool
REBOOTED as [Redactor](http://wordpress.org/extend/plugins/redactor/)
Cleans up commenters' bad language.