[stevehertz]

David, try to stick to mechanical means of removal, ie a stiff brush at first, then a fibre stick and if necessary a bit of very smooth wet/dry paper, trying not to remove the shiny plating. Neutralising liquids only spread the stuff. I've got a collection of toothbrushes and that kind of thing that I use, plus a powerful battery powered blower. Then like I said above, use a contact cleaner to 'prime' the contacts once they're clean and gleaming. Apologies if you're an expert on this kind of stuff! But I've done quite a few in my time. Oh, and I never believe what people on auction sites say. I guess he meant he'd got rid of the excess..