Any product that contains sodium or potassium hydroxide will remove the anodizing. I generally use a solution of drain cleaner in water. As it works, the surface of the metal will turn black. This can be easily wiped off to check your progress. Once the anodizing is completely removed, you can then rinse and polish. A few precautions: 1) the solution is caustic so be sure to wear protective gear - gloves and eyewear especially. 2) Check progress frequently and stop as soon as the anodizing is gone. The solution will continue to eat away at the aluminum if you leave it in too long. 3) The polishing process may require you to use successively finer grits of wet-dry abrasive paper to get to a nice final polish. If you just try paste polish, you won't get the best finish.

Good luck.