Doc wrote:

Or,, a muslin wheel & tripoli compound, on the exterior surfaces a big
wheel
would cover alot of ground , and a dremel in the tight spots.

The problem is getting into the little pitted spots. Even a dremel isn't
going to do the job. I need something that will do the cleaning chemically.

You can't clean away the little pitted spots because it isn't
contamination, but missing zinc that is the problem.

For just general work in close quarters around the braces, you "rag"
with cotton tape, or for small detals, flat shoelaces.

A novice trying to buff a trumpet is likely to have it caught by the
wheel and flung across the room and smashed... there's just too many
things that can snag.