Might a workable solution be to disallow posting privs to ALL boards on the site until the member has been approved by a Mod, with the exception of a board specifically set up for intro posts?
Then, tell new users (after that have run the gauntlet of Midaski's verification) they must post a post in that forum and THEN they get approved.
If the post is a picture of a real-life Klockenbooty model doing unmentionable things to a man with an Ogre mustache, then we know they are not a real person. If the post is "Hello, I like the Empire and I want to paint models" we know they are a real person.
Or a particular type of fetish-porn-spam-bot, take your pick.
This would concentrate the spam into a single board which people could ignore at their pleasure.
Just a suggestion for "the next stage" in the arms race. You have my sympathy, guys - thank you for your service.