Hi stfennema -- welcome to the forums! A variety of products have been discussed for blasting Airstreams. One example - plastic beads for clearcoat removal
. And soda blasting
. Here's a voice of very good experience on the subject of stripping - InsideOut
Test in the proverbial inconspicuous place of course. You could end up with a matte finish. Over-aggressive working could burn or warp the aluminum. Just don't power wash anything or you could loosen up clogged, unleaking seams. Airstreams weren't meant to breathe.