What have you had good results with cleaning track using an Aztec track cleaning car? Various folks have suggested Goo Gone, Nail polish remover, etc...Nail polish remover has acetone, which is both highly flammable and damages plastic, so i don't want to go there. Even non-acetone nail polish remover is flammable (contains ethyl acetate i think) so i'm not sure that even makes sense. What works well? Thanks.