I don't recall seeing anything thay you can spray onto dull and pitted aluminum and wipe or hose off giving you "like new" results. Sanding and buffing is what lies ahead of you. The shinier you want it to get, the more finger nail damage you will suffer.
As Farmall mentioned 400 grit should do the heavy work unless there is pitting. Oh and funny thing about that silvery colored aluminum, when you sand, buff, and polish, it comes off black. Now look at your hands, see all the fine lines off your knuckles, and see the edges around and under your fingernails, now picture them filled with black soot. ENJOY!