I don't think it can be done. Over the years, I've experimented with every polish, cleaner, and chemical known to man. There's just something about black guitars, especially vintage Gibsons, that makes them impossible to clean. So, here's a two part question for the forum: what, in your opinion, is the best way to clean (not necessarily polish) a guitar, and what is the most difficult guitar to clean?
Here's a partial list of stuff I've tried:
Martin, Dunlop, Preservation Polish, Gibson, Fender, plain water, water with dish soap, windex, water with windex, novus 1, 2, and 3 (watch out for that 3!).