I was told by a friend who is a big Zakk Wylde fan that he uses a wah-wah pedal and pedals it fully treble for his pinch harmonics, then returns it to a lower position for the rest of the song. i.e. let's say fully bass on a wah is 0 and fully treble is 10. So, he'll play the whole solo/song with the wah at 4, but for each pinch harmonic, he'll quickly flick the pedal up to 10, then back to 4 to continue playing.

Anyways, that being said, I don't know any Zakk Wylde outside of any Ozzy being played on the radio.

Hope that helps!