I know MBV uses reverse reverb, and while the PF doesn't have that, it does have Crystals which is pitch-shifted reverse chunks with reverb. You could try setting the reverse time(s) (in tempo mode) to 1/4 note or a 1/2 note, and setting the pitches at +/- 3-9 cents, and then using lots of reverb and not much feedback. It won't sound like crystals anymore, but it might get you what you're looking for.
