I have a question about the appropriateness of using an ultrasonic cleaner for certain applications. For instance, I have a gun (hopefully pictured below) that has a patina on the receiver. I can see a little case color on the tang but have no idea what's below the patina - clean metal, or case colors??? Should I try submerging the receiver in an ultrasonic cleaner? This is a Hunter Arms manufactured 410 of which there were less than 250 produced, so I don't want to do the "wrong" thing.