I would believe that stripping signatures, mailing list footers, etc. is a common wish, so I'd suggest that a question, something like this, is added to the FAQ:
"How can I have MHonArc strip a mailing list footer?"
The answer should provide a simple example, including the filter 'wrapper' as mentioned above.
-- Gunnar Hjalmarsson Email: http://www.gunnar.cc/cgi-bin/contact.pl