I can tell you what I did. I had a pretty noticeable dent, probably about an inch deep and 4-6 inches wide.
I used marine puddy I got at bass pro, and in a few other places I used JB Weld puddy. I just treated it as a body filler.
I wire wheeled it down really clean, then started applying layers for the deeper dent. I think I had about 4 layers and I made sure and brought the last layer above flush. Then I sanded with a mouse sander using 80 grit until it gets close to flush. Then I used about 400 and finished off with a wet sand of about 1500. Primed with self etching primer and painted. That was last year and it still looks great and its undetectable.
One thing I will add is when this stuff fully cures.......it takes some time to sand as it cures harder than the aluminum.