I just used one to polish the bolsters on a stockman.
I found that it took pretty high speed and high pressure. Trouble was, it would juuust start to do the trick and the buffer wheel would strip on the mandrel...just start slipping.
I think a can of Brasso and a rag might be a better idea.
Oh I used some green rouge on the cloth wheel to initially clean it and that did the trick on the badly corroded bolsters and pins that I had.