mawd

Hello, My wife has been playing around with polycarbonite molds and likes them alot except that now the older ones have gotten some sort of dirt on them and the wax gets a nasty finish on it when cooled. we've tried using cleaners and scrubbing the molds but nothing has worked. we've tried solvents and WD-40. does anyone have a trick on how to restore poly molds so the candles come out smooth like when they are first used? thanks