I've used wheel cleaner formulated for chrome wheels, it's usually stronger than the other formulations. Don't use them on uncoated aluminum wheels though, the acids will stain the surface.
Should never let your wheels get to the point that they have " brown baked on crud" on them. All you have to do is wash them off once in awhile with car wash soap. It amazes me to see vehicles driving around with brown front wheels and silver rear wheels.