the secret is zakk is the fu#kin man , but zakk dosent use his rotovibe for the pinch harmonics , he just uses it mainly for clean songs like road to nowhere, ever since i heard of zakk wylde ive done pretty much every thing i could to play and sound like him because hey who wouldnt wanna play like the master himself , just work on your vabrato as much as possible , oh yea what zakk does alot for his PH is he will slam the wah pedal down and then pull it back up, i cant really think of anything else right now thats where the whole 420 thing comes in effect but if u have anymore questions about zakks playing just ask ive studied this man down to a t i , uhh peace out