If the items you are looking to polish are aluminum as I assume they are, you are going to have to coat them with something or they will soon return to their current state. Aluminum oxidation actually protects the metal below with a protective layer of oxidation. I'd probably wax them after cleaning. Spray-on clear acrylics will flake off like old varnish, but sooner.(g) I've heard good things about Colonite as well.
“Scientists are people who build the Brooklyn Bridge and then buy it.”
Wm. F. Buckley, Jr.