I used to use the spray down, and scrub every nook by hand with a toothbrush wrapped in a towel, but I've moved on. I picked up a nice brush with bristle with soft tips but firm farther down, I just spray down the wheels with water and some cheap wheels cleaner, scrub for a short while, and spray off. The wheels get cleaner and its easy enough to do every few days when I wash my car, so brake dust never builds up anyway.