I've used evaporust to clean out the seam on rallye wheels with great results. When I'm done I paint brush a little PPG DX metal cleaner in the groove, and then pour a little DP epoxy primer in there and roll it around.

On a standard steel mopar wheel with the 4 small openings the evaporust would just run out the sides and not do anything. You can take some clay and cram it into corners to create a small dam that will keep the evaporust in place. In order for it to work the area has to be sumbmerged in it for several hours.