Meta: Ooooh, a clever, clever idea from the OSSU community discord. https://ossu.dev/#community A honeypot channel that triggers an auto-ban of any account that posts there (presumably excluding mods :D).
Trouble is, in my experience very few bots post to all channels.
What channels do they typically post to? Perhaps apply thumb rule on those? And make a #jobs-honeypot channel (or something similar); basically some common keyword that is always targeted by spambots?
The problem is not that big to warrant extensive automation. :) And there are no typical channels, it's somewhat random. Most of the spam is probably via DMs anyway.
And most of the spam is from people, not bots. At least, so far...