Can't say much for your parents, but there is some kind of soap that auto mechanics use, and that stuff works miracles getting all kinds of stuff off your hands. Haven't needed to use it in a while, so cant think of the name, but should be able to google it.
EDIT: Here is the link for what it looks like: http://i1083.photobucket.com/albums/...ngecleaner.png
Bookmarks