Yes, there are plenty of alternatives. The finish on the aluminum is quite durable.... some sort of teflon-like material applied by Alcoa during the manufacture of the aluminum sheets. But I think it is wise to keep as much UV off of it as possible. I just wash with Joy and a soft brush (car finish brush) and then whip dry to remove any water spots. Then I apply Walbernize:
It is easy to apply and buff. I do this a couple times a year.
P.S. Do not use Walbernize on the rock guards. They are made of brushed SS and Walbernize gives the surface a blotchy look.