Originally Posted by wschruba

If you're looking to clean the brake track, you don't really need to use anything but soap and water (for dirt), and a flexible abrasive for the track itself, if there are stubborn spots.

In the USA, they are sold under the name SandFlex--you would want a fine grit version; it's best to think of them as an eraser with grit in them. You can usually find them in [very] well stocked woodworking supply houses, sometimes in model train/hobby stores (for cleaning tracks). If that fails, you can always buy the horrendously over-priced rebrands that Hozan or Mavic sell.