I applied 2 coats of Hard Body to my wheels. Silver, machined face, clear coated. I do notice that a lot of brake dust does end up washing off with just a spray of the hose but nowhere even remotely enough that it could be confused with being 'clean'.
I don't know if that's normal or if Hard Body just doesn't work with brake dust. I'll try and take a photo of it next time I wash the car.
I also have G Techniq C5 wheel armor on my other car and it's about similar. There's no way it can be just hosed off without getting there and giving it a good proper clean with a microfibre mit. I even wheel waxed over the top of the C5 to see if I could get a better result. Those wheels are a satin black so I figured it was something to do and a clear coated wheel would be better but it's seems pretty much the same.