I got tired of the spam a while back, so I decided to do something about it. I made a Bayesian spam filter (the same type of filtering used for email). It's surprisingly effective, and very easy to use. It also comes complete with help (read the readme or type .help in either a channel or in game).
If you find any spam messages this doesn't catch, or bugs that need fixing, feel free to post them in the support thread in the BAPS forum.
BHFiles Link: http://www.bhfiles.com/files/Diablo%20I ... Filter.zip
Source code: https://github.com/lord2800/SpamFilter