I use whatever is lying around from my motorcycle: usually Turtle wax. But let me tell you something else I discovered, incredible for cleaning parts: there is some pump bottle Naval Jelly and Aluminum Corrosion remover. I spray it on (sometimes both at once, depending on the condition of the part) in my basement sink, brush overall occassionally asa I'm doing something else for 15-30 minutes. After it soaks, I scrub with a small, stiff plastic or wire brush, rinse in hot water and dry. Brings the aluminum back to new without much effort, removes any rust too. Follow up with disassembly and semichrome if you like.
Ted, Berkeley