Would it be acceptable to reduce the lifetime of spam and/or trash messages under Configuration:Class of Service:<class>:Advanced?
Note that by setting up different COSes, you can set the value differently for different users.
See also:
[SOLVED] scheduled empty trash emtpy junk for users
Also if I understand the original poster's request, if you really don't want server-based content-based filters but you still want to use blacklists, you can just turn them off at Configuration:Servers:<servername>:Services:Anti-Spam. This might help:
[SOLVED] Disable AntiSpam
Blacklists etc. are handled under Configuration:Global Settings:MTA which is a completely distinct system.