Not sure how to get your rims clean at this point but maybe a new kind of pad would help you in the future.
I was hand washing my rims weekly, sometimes daily to keep the brake dust off.
I would drive it to work and wipe them down before going in to work. can you tell I hate dirty rims! LOL
I took a chance and ordered from a guy on ebay that said his pads leave very little dust.
Now I only hand wash my rims once a month, if that much.
I still wash the car a couple of times a week going thru the "no touch laser wash" and my rims clean up nicely.
I do not know this guy but I am very satisfied with the pads!
You can search the ebay seller by name... foreigncarpartsonline
here is some info... $70 and $5 shipping
Akebono EURO ceramic disc brake pads feature advanced ceramic friction material technology perfected by Akebono.
Original Equipment Manufacturers (OEMs) who have approved the Akebono European technology include Audi, Mercedes Benz, and Volkswagen.
These pads are an ultra premium upgrade to OEM supplied brake pads and are engineered for drivers
who want to maintain European pedal feel and improve vehicle control while minimizing the dark and difficult to remove brake dust.
The new EURO line delivers improved stopping power combined with unprecedented Noise, Vibration and Harshness (NVH) control,
extended pad and rotor life and noticeable reduction of brake dust on todays open wheel designs.
Hope this helps,