I’m afraid if that were true you’d not have written this post. You’ve got bots who are more clever than the “watched words” feature. Also, it’s a pretty good bet that they are actual humans (though bots may have gotten so much better in the past year that the humans that were creating new accounts have lost their jobs).
The other thing you could do would be to approve all posts from TL0/1 users. If you don’t get lots of new legit users who’ll be sad if their post doesn’t show up immediately, that could be a “straight forward” solution.