If they are uncoated Billet you can use a heavier grit polish.
Ed at Pipe Dreams sells a kit with a ball polishing buffer, polish, and 2 bars of jeweler's rouge. One is heaver grit than the other. It’s a 3 step process but turns out great results. The kit is like $30. You can always use “White Polishing Compound”. That Mothers ball you have is too coarse. You need a polishing ball covered in cloth that fits in a 3/8’ drill and let the speed of the drill do the work for you.
Once you get them to your satisfaction coat the wheels with “Wheel Wax”. It’s a product especially formulated to repel brake dust.