Pinch harmonics need lots of distortion to ring out. They're barely audible without being amplified. Choke up on the pick so that some thumb skin and the pick hit the string simultaneously. Then move the position of where your picking the string around by millimeters until you get one. There's a bunch to hit on each string for each note. You just gotta find a sweet spot above the pickups where you can get 'em. Hope that helped.