Do any of you have a suggestion for something you can brush onto big bronze seacocks that have a lot of verdigris oxide on them to restore them to at least close to their normal reddish-brown color?

Mine have been like that since I got the boat (about 4 years). I could care less aesthetically, but I'd just like to be able to tell whether the hose or one of the fittings is weeping at all, however gradually. I figured if I could clean it up well initially, i'd be able to spot a little trail of green if there is any kind of leak. My guess is there's no weeping, and they just look the way they do because of where they are.

-- Paul