Hello,
I don't know if this already exists:
two channels of delay, with delay time randomized by the order of tenths of milliseconds, randomly alternating a positive vs. negative delay and positive vs. negative slight change in volume.
This could be accomplished alternatively stretching the waves in time without affect the pitch, so you have randomly a slight delay similar to have two players running same part.
Obviously the two channels must have different sound, so this effect could make use of the double path configuration of the rig. you set two paths, one with distorsion, one clean (think at an acoustic sim on it).
A stomp with random time stretching located on both the paths would accomplish the task.
