Does anyone have experience or knowledge of how to clean faux antiqued brass from zippers in particular. I would also have to watch out for the leather, not to ruin it. Some of the antiquing on some zippers are quite dark, almost black I say. I wouldn't mind if it were just darkened a bit. Here's just an example. I don't really have anything to test it on and I'm not sure if the methods for cleaning normal brass from real antique will even work.