This is my problem. I used the #2 cutting polish on it and 98% of the black brake dust was removed,but it took an hour or 2.
All the other polishes just polished over the top of the black.
Im hoping now most of its removed I can use a more gentle polish to keep them clean and shiny.
Mine never had a clear layer on top that I could see. Either it never had one,or it was removed with some brutal polishing by the previous owner.
What I would really like to do is remove the wheels and give them to a metal polisher ,like Cadfather.