But
now your clear coat is gone, so the brass fixture will now start to
tarnish again immediately, but this time it will tarnish more
uniformly.

It if brass isn't subject to wear you can "clear coat" it with a a spray can
off "Clear coat."

Even if it is subject to weak, the clear coat might help. The wear may
take off the coating but the handling often postpones the crud formation.

And this only really works when it is a solid brass
fixture. Many inexpensive fixtures are brass plated plastic or pot
metal, with a very thin layer of brass. Removing the clear coat and
polishing can easily rub right through the thin plating.

Plated sheet steel is more likely.