This must be what you were inquiring on the wet blast idea for. There are medias out there (corn cob, walnut shell, and various plastics) that you can use dry. Also there are paint removal discs from 3M that work amazingly well. All will work on an aluminum boat. If it has multiple coats of paint, honestly since they took the methylene chloride out of paint strippers, you'll be on it for weeks using them. Mechanical is a lot more work, but it's a lot faster. Wet blast is fast, but even wet, it's a colossal mess. That was the great thing about the wet baking soda system. The baking soda dissolved when it got wet. No cleanup.
this is the paint removal disc from 3M