toxicTom: While I've given up on systematically reporting - I mean there are 4 new threads per minute in TW2 - I toyed around a bit and came up with a new bookmarklet.
http://pastebin.com/5igxmQ6v This one is not to used on the "open thread" view, but rather on the outside.
It will replace the "favourite" checkboxes with "mark spam" checkboxes. The heart at the top is replaced by a button. The "spam" button will open every ticked thread in an iframe and mark it as spam. This will annoyingly create loads and loads of "Thank you" alerts, but at least they will show you that it worked.
The script could certainly be improved, but I simply don't have the time for it right now. Got some real work to do, too ;-)
Hmmm... the link I used above didn't work. Here's ToxicTom's original post.