Fred suggested:
One idea I have is a ban for one day for each time the perp uses the words "stupid", "trash" and "crap" to describe another's edit. This could add up to a year or two for some of these folks.
I like the idea of short "time-out" bans. I suggested this a couple of years ago. Also, it seemed to work fairly well the time Erik M. (Eloquence) "banned" RK for just under 24 hours last year.
My experience is that time-outs work better than total bans. A ban is like death or torture: it satisfies one party's desire for revenge, but at a terrible cost (hint: think of how the other party feels, waking up dead or maimed...)
Kindly Ol' Uncle Ed