A good ass kicking is the only thing I have known that helps.

Roll them in a carpet and have the performers drag them off. At least that's what we did in Julius Caesar.
Seriously, the one problem child we have in our workplace is more of a very subtle (and I suspect not concious of it) gaslighter. I try to counter the effects and defuse it before it happens. I think it stems from this person's ambition and very sincere commitment to the workplace.

Most backstabbing I've encountered so far has been from unrequited crushes, and so far I've just done my job as usual and let things sort themselves out. But if someone seems determined to accuse me, I just change jobs.