How to get "restores PP" patches to work?

[Geek2theRight]

I've been playing Stick of Truth for the first time in a while, and I got some patches for my equipment that sounded good, but which did absolutely nothing. The regain PP on fire, gross out, etc. line of patches. I made sure that I had the appropriate elemental effects on my weapons, and the corresponding "restores pp" patches on my armor, and . . . nothing. I'm not sure if they're bugged, or if I'm misunderstanding how they work, but I can only regain PP with items. Anyone know what's up? (I'm Jew class, btw, if that matters.)

[WallaceTheSane]

Not sure exactly how it works, but I think a lot of them are from melee only and only when you hit perfect hits.