But personally I think firearms looks so good after the brass tarnishes.
All depends as there are some that I will never polish. Then there are those that it really doesn't' matter. ...
The smell of Brasso, always takes me back to my military years and it is good stuff. I was given a plastic jar of Mother's Mag and it works well also. ..
"If it's brass, polish it; If it's steel, primer and paint"
Be Safe !!!