Cleaning my rusted rim, I used 3 different products in equal amounts: Brasso, Mr. Metal, and CLR (ranked from best to worst). CLR may be good for calcium & lime, but a failure for rust. Mr. Metal removed about 50-60 percent of the rust. Brasso performed the best. It did not remove all the rust, but I will tackle the rest with aluminum or steel wool. Brasso is fairly inexpensive and easily available; I got mine at Smart & Final.
http://www.flickr.com/photos/ccozic/7189848520/in/photostream
http://www.flickr.com/photos/ccozic/7189848520/in/photostream