I'm interested. How?

I once proposed captcha (self hosted on relays) to keep the bots ou and felt like there was a bit of a cold reception. (In retrospect, not shocking.)

Or we could do some kind of vouch. WoT score and PoW would probably not work against motivated botting. It would be realistic to create a no-bots relay somehow though, I'm sure. Whether you like bots in general or not, proof-of-humanity is going to be an important option.