Aluminum is ok to shoot. If you find it cheap- I don't think it's a worry for gun wear. I still have some blazer from way back... (it shoots fine but I just hate to mix aluminum and brass!) I use it when I shoot where I can't p/u brass.
Steel- I avoid, but I don't own any weapons made where steel ammo is prevalent, otherwise it wouldn't bother me to use it on a gun designed to run on it.
That's a lot of work... it may be much more "profitable" to just sell the ammo lot at a discount and buy new brass or components. If your time is considered, you'll come out further ahead that way.