How can I remove baked on brake dust (that looks like a rust color) from my alloy wheels?

I have a BMW 328i with Alloy Wheels. The brake pads and rotors needed changed and the brake dust and shavings from the worn down pads/rotors is crusted on one of my wheels. (The brake pads/rotors have since been replaced, but the alloy wheel is still in bad shape!) The corrosion is very thick and hardened on the wheel. Initially I thought it was rust, but further research revealed that alloy wheels cannot rust, but more likely that it is corrosion from brake dust. Please Help!!! What product and process do I need to use to get my wheel looking new again? Thanks!