>>/19237/
Such mechanisms never work. Look at every attempt at implementing automatic censorship to filter out swear words. It affects a lot of innocuous posts made by regular users, and doesn't actually deter wrongdoers in any way, as they can simply insert non-ascii characters between filtered words. In fact, the spammer already does that with every of his posts, inserting spaces or weird characters, both to avoid people from autohiding his spam with dollchan and to circumvent the inbuilt endchan's unique post restriction ("r9k prevented this message from being posted" or whatever). Plus, a lot of what he posts is actually just newspaper articles or slightly edited copies of other peoples' posts, not some specific original posts with discernible slang terms. And even if you had a script that worked (which you never will for the reasons stated above), you would still have to persuade everyone to install dollchan, so it could automatically clean up deleted posts on the user's side. Also, the script would be quite bandwidth hungry, as the spammer can shit out several posts per minute, so you'd need to parse an up-to-1000-posts thread every minute to delete it all in time.
If you really believe it can be done, despite all the mentioned difficulties, why haven't YOU done it yet?