i made a bunch up out of cork, and probably spent waaay too much time playing with my dremil. most of them i left raw cork, and colored with a sharpie.
i did used vinyl lure and jig finish on a few, the vinyl seemed to carry the same elasticity that got from the cork.
however i dont like to use it at all, there are 4 sides to the jar.... 4 sides have warning labels... stuff is nasty until it cures, and whatever you do, do it outside. when it was first given to me, i burped the jar in my living room to see the consistency ..... about 2 days until the smell finally cleared out... come to think of it, ive only used the stuff once, thankfully it was gifted to me...

on a side note, epoxy is probably your best bet, what are you making them out of?

-spoof