As mentioned above, scotchbrite pads work a treat. I use the one that you fit onto your drill, it makes short work of oxidisation and the pesky clear coat on the alloy cases. Just be careful and do it all in one direction and dont push too hard. This is no place for your fancy moves, save them for your bedroom!
This will give a "brushed" finish, if you want ultra shiny, just go over it after the Scotchbrite with some 1000 grade wet and dry, then autosol, or any good silver polish (I use Silvo with good results).
Good luck!