So I decap then clean using dawn+lemishine in a large ultrasonic. The brass doesn't look "brand new" but it is still nice and shiny and I always have an anneal mark anyways. I imagine you get more of a "brand new" look from wet tumbling with media because a layer of old oxidized brass is removed via friction. If that is the case, wouldn't ultrasonic be better for brass life considering it doesn't remove the outer layer every time?