Well, his way is to bring them to such a mess that they actually couldn't talk...but that's the great thing about being a genetist and the like, he can reconstruct it, and with his knowledge of the human body, he can really push the boundaries of pain. Really, the only problem he has with torture, is not going too far and killing them, but going too far and breaking their mind.
Imagine torture, but with your senses, especially touch, quadrupled in intensity.
-"I'm sophisticated, charming, suave, and debonair, Professor. But I have never claimed to be civilized."