I metal detected a steal soccer coin toss coin once. It was heavily rusted. It looked cool so I tried putting Brake Free on it. I let it soak for a couple days. It had virtually no effect on the rust. Once a coin rusts deeply it is over. And OP, I bought a reprocessed PDS set of 43 wheat cents for $1 total. sure, they are considered PMD due to the recoating but they look like beautiful MS coins despite being virtually worthless. So there is no reason to settle for a destroyed coin just because that's what you have on hand. Pretty ones can be had for cheap.