Actually that example you’re trying to replicate is very subtle and well done.
I Gave some incorrect advise, in that, if you use the CC Bender for a rubberband snap back you need to match the cell wall just before the separation with the Amount on Bender at 20, since the first line of the expression is:
amp=20; //amplitude (pixels)
I hope this make sense.
I don’t know how Aharon’s aep is setup as I’m AE6.5 handicapped (me Bad), but using Bender and the expression will give you the motion you’re looking for although you might have to use it differently than I outlined. You might need to put it on a dupped layer and (Alt + ]) cut it, so it’s in the proper part of the vibration to match your puckered cell wall.
Why do I et the feeling I’m making this worse?