Try this version:
http://www.usenetexplorer.com/temp/ue58b32.zipI've added the log option in edit menu->properties->kill filters, built in filter. It needs to be enabled on every run as it may write a lot.
You can access the log file fast edit menu->properties->general, database folder, click "Open" and then click on log.txt
I downloaded last 5M headers, what I see it removed 44K single messages posted on January 19 which are parts with randomized subject and author spread over many newsgroups.
But if you will see something wrong let me know.
I'll add it in the next version, I had a thought about it since I have such log option on the server, but it didn't make it through.