That's exactly what I just finished using, and got about a 90% result. I only had a limited selection of brushes for the Dremel, didn't have a metal bristled tooth brush with me and that's what would have made the difference. I'll raid the gun cleaning kit at home and finish up next weekend.Typically I use metal polish and elbow grease. For hard to reach spots the dremel works good with a small wire brush. I then polish again and cover with a thin coat of winch grease to prevent further oxidation. It seems to work ok.
I have marlon seacocks so I probably wouldn't worry if it wasn't affecting the operation. However, a stuffing box though has to be disassembled regularly and I worry about parts seizing if I don't keep the oxidation at bay. If the threads are damaged it will cause an expensive and difficult repair.Why? The oxidized copper patina itself is a barrier to further corrosion. 'take care and joy, Aythya crew