I don't have experience with the CG rinseless/waterless but I do with other products such as ONR. All I can say is "do it". Rinseless washes are great. Often I opt for rinseless washs even when I have a water source available.
They're not expensive, the ONR concentrate goes a long way. I'm sure the CG product does too.
As far as fighting BMW brake dust, the performance should be the same as regular car soap. If you have a good sealant on the weeks, it will come off no problem with soap. If you don't, and you've let it build up, use a dedicated wheel cleaner, then apply sealant. You'll probably want to use wheel cleaner when you're at the self serve, since most wheel cleaners like to be rinsed.
Check out the Garry Dean wash method on you tube, I prefer it over a two bucket setup.
2005 ///M3 Estoril Blue/Gray SMG
2012 740i Black Sapphire/Black Dakota M-Sport
2010 328i Titanium Silver/Black Dakota Sport [wife's]