I just had my roof redone, and despite my best efforts to keep the pool covered, there are a few (maybe a dozen or so) small (size of a pin head) what seem to be tar spots. They are all at the water line, and when I rub them with my finger they smudge. Is there anything that's good/safe to use on vinyl liners to remove something like this? I have stuff called "GOO GONE", but it says not to use on such things a leather, and rubber.... :?