Most wheel cleaners use similar ingredients as liquid carpet cleaners.
They are designed to seperate oils, grit and dirt from synthetic and wool materials
I have found that a good quality brand of carpet cleaner works well to remove the brake dust build up and is much cheaper to buy than the car care brands.
Just follow the same instructions.
I spray on the wheel, leave it on for 30 secs to 1 min then wash off with a High pressure unit (Karcher). If your wheels are really dirty you just use an old paint brush to work it in whilst you apply the cleaner.
I have been told that these chemicals will not harm the wheels or tyres.
The plus is that it also works on your car mats