Sonax is good stuff, but its nearly twice the price of P21S gel, and a smaller bottle to boot. Actually, what I have been using is S100 (motorcycle product arm of P21S) total bike cleaner, which is the same as Total Auto wash. Its cheaper still and I can use it on wheel wells, the motor, dilute it for interiors etc...it works just as well and is a much more versatile product. I get it from the local Harley dealer.

 

Looking at the 5 liter price, they are about the same (+ or -) I may have to try the Sonax one.

 

I've had no issues but then I painted my wheels a dark gray color, so wiping off with water and car wash detergent gets all the brake dust, and the bits of asphalt thats stuck on usually comes off with a bit of tar cleaner and/or elbow grease easily enough.

As others have mentioned, once you get the wheels clean, applying wax or some other coating on top of any paint/metal will make future cleaning less scrubbing intensive.