Don't use PUL. It will not work as an absorbent layer since it is made from plastic. It works good as a bottom layer for lap pads to keep from getting your lap wet. I have also used it as an inner water proof layer for back packs, wet sacks and lunch boxes. Towels, uhaul pads or mattress pads make good choices for an inner layer.
I misspoke when I said PUL. I was thinking of the absorbent layer in cloth diapers, mama cloth, etc and I know PUL is in there too to keep it from "leaking" - just said the wrong thing and now I can't even think of the stupid name of the stuff I was originally thinking about. Thanks for the correction though!
I bought towels last night and I'm thinking of getting a uhaul pad today so I can test both options and see which one I like better...