[Melusine]

Aelia, I asked the same question here before and have since found out what works best. I do have a speechcraft of about 55 and 100 Personality but even at lower levels this worked.
The trick is to get their disposition really high first, by bribing or admiring. Then taunt, taunt, hope you're successful, watch the disposition drop and when it nears, say, 40, bribe/admire it all the way up again, then taunt some more. It does take a long while but it works.