The problem with the limiter is such that those actions will do no good if they really don't want to comply. If you switch them to spec, they can just re-join and it will give it to them (that's the whole problem), same with kicking. So I would guess you'd be better off slaying them or setting them on fire (lol flaming vagabond) if a warning isn't sufficient. Of course, if they're really stubborn, there's always the 5 minute break!