Best way to clean non-coated cast aluminum?

Best stuff I've used is Boushe (sorry, I don't know exactly how its spelled, but its probounced like "bushy") Gte the pink one as its the HD. It works like magic, but it is an acid so be careful
 
not to steal your thread but, i made a shift knob out of steel, is there anything i can do to polish it or do something to make it shiny like how aluminum gets when you polish it? thanks