I don't know what results you are getting but the spam messages in the
sci.engr.welding group that I see are flagged as "this message no
longer available". You can set the "Purge" selection in the Group of
AGENT section to delete these "no longer available " messages which
clears out the garbage.

Maybe this will help a bit./

Bruce in Bangkok
(brucepaigeATgmailDOTcom)