Eezox.
I have a boatload of chemicals acquired over the years, but for the most part, they are all gathering dust now. (I did use some Outers oil last night to silence a squeaking office chair...
)
Since I discovered Eezox about two years ago, I use it for CLP (Clean/Lubricate/Protect) on all of my pistols, rifles, shotguns.
I'm not sure if it will remove lead or copper fouling--after the first few applications during regular cleaning, I have not encountered buildup of copper or lead.
However, it leaves a very persistent, very corrosion-resistant film which also resists fingerprints on blued guns. It works just as well on my stainless and polymer pistols, and I use it on wood as well.
I had a friend who left his Weatherby's wooden stock in the attic for two Texas summers (rifle was wearing synthetic in the meantime) and when he pulled the wooden stock out of storage he was heartsick--the beautiful walnut was sticky, the finish seemed to be melting. He tried Pledge and several other wood treatments to no avail. I had recently given him a can of Eezox to use on his Kimber and asked him if he'd tried the Eezox (having no idea what would happen, but little to lose)...within an hour he called me back saying that his stock looked as good as new. A year later, it still looks just as good.
I buy it on eBay as it's hard to find locally. I generally buy about six cans at a time to spread out the shiping over a larger order...and I always give away a can or two to friends. For some reason, each succeeding order is a bit larger...
FWIW, I have absolutely no financial interest in Eezox. Don't sell it, don't know anyone who does. I sure do like the product, though. Even smells good. About time to place another order...