[C. Charles Hahn]

I second the suggestion of Sonax; a similar alternative would be 1Z Colourtec which I find to react/dissolve brake dust slightly faster.

As far as brushes/tools I'd recommend looking into some Wheel Woolies; they have multiple size options as well as one with a curved handle to get the back side of spokes/etc.

 

[C. Charles Hahn]

I just use water.

Remember that water alone cannot provide lubricity for the brake dust and road grime that gets stuck to the wheels; you will need something more than just water to safely carry those particles away without causing damage to the wheels over time. You'll start to notice scratches and hazing all over the finish pretty quickly if you're rubbing the wheels with a brush or cloth that only has water on it.