What about doing electrolysis? You can you tube it. I still have yet to do this to mine. Otherwise I saw on a show that used several detergents and tumbling in detergent. Possibly even using a de scaler type cleaner.
Clean them after the day trip then. Is it possible to have wire long enough to have multiple coins or items connected to it? That way not doing one at a time.Electrolysis works great on a single item but a pile of clad would take you forever to do.
[/QUOTE]Here is a link that shows you the exact steps. I bought a tumblr and used these instructions. It worked great.
How To Clean Clad Coins
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