Interesting comments there from both Nigel and Landes on how to remove the corrosion from copper wires. It's something I hadn't thought of, but it takes me back to my days as an apprentice onboard my first ship. On that vessel, amongst other work, one of my jobs was to clean the brass and copper around the ship's wheelhouse. That included the covers over the magnetic compass and the gyro repeater located on in this case, the aptly named "monkey island" deck. These were cleaned weekly and in the space of one week each helmet had turned bright green, and represented a good fifteen to twenty minutes each of cleaning time to bring them back to their former glory. At one of the ship's ports of call in West Africa, a couple of the seamen went ashore, and each came back the proud owner of a small monkey. In due course one of the monkeys escaped while the ship was at sea, and no prizes for guessing where it had made its home. One morning, and shortly after the Chief Officer and myself had been brought a slice of toast each and a cup of tea, the monkey ran out across an awning spar and reaching down it was able to steal the Chief Officers slice of toast, and then ran back and sat on top of the helmet for the gyro compass where it downed the toast and then urinated over the helmet. The green verdigris on the helmet disappeared in very short order, making my job later that morning very much easier than it might otherwise have been.
So my point is that you might be able to use a waste product that is more readily available even than lemon juice!!