Heads-up for future reference, as I'm doing a lot of metal cleaning and degreasing with my antique car restoration project, but you can get quarts of LA's Totally Awesome cleaner at Dollar Tree for $1.25 and it works just as well, if not better than Simple Green for stuff like this. Just dilute it to about a 1:4 ratio of cleaner to water. I've been going through gallons of the stuff lately.
It will also remove most paints if you let it sit long enough, mostly because of the alcohol in it.