I buy plastic (plastisol) by the gal. for pouring my soft plastic lures. If I want larger bodies, I heat the plastic to a pouring temperature and dip the bodies in a few times to the desired thickness. Sometimes fish - especially bass - go after the larger bodies better especially in low light or in deep water. I dip grubs with different tails, tubes, soft plastic sticks and jig trailers. examples:
The front of this Yamamoto Kut Tail worm was thickened with a plastic dip:
Coated this worm's front with pumpkin colored plastic (not fond of messy dyes):
coated tube bodies (Joker tail replaced tube skirt on the right):