[LWJ]

So Aluminum is HIGHLY reactive. It typically oxidizes and self seals. It also reacts to both base and acidic cleaners. Use lots of caution. I would pressure wash with water and maybe some mild soap. It really shouldn't need more than knocking the dirt off. I know some people polish their Aluminum stuff which looks great. But, the maintenance is a real chore.

Source: I sold millions of dollars of this stuff once upon a time.