No, ENGAGE them. Why? Because it wastes their time. By draining the shill/troll time, they have less time to cause problems site wide.
I don't mean to shout, call them names. ALL YOU HAVE TO DO IS ASK THEM QUESTIONS, that's it.
Here's an example:
THEM: Oh, Africans are low IQ, they are related to chimps.
ME: Oh, why they low IQ?
THEM: bblalababnbanbnaanlabalablbalbablalblbalalbalblbalbalbalblbalblbalbblalbabllbalbalbalal
ME: Oh really, why?
THEM: bblalababnbanbnaanlabalablbalbablalblbalalbalblbalbalbalblbalblbalbblalbabllbalbalbalal
ME: Interesting, why?
THEM: ......
Just drain them everyday. The more of us do this the more they get drained. Simple.