Cleaning Coins Wrong Or Right

There is no such thing as good cleaning, with the exception of a pure acetone soak to remove any biological spots or stains. Even then, NO WIPING. Soak then rinse in pure water and let it air dry.

A coin that's been rubbed with a cloth destroys the surface of the coin and removes remaining luster,and is usually detectable as cleaned.

Cleaning drops the value of a Coin through the floor.

@Kevmstewart, I think that you will find almost universal disapproval for cleaning coins here on CCF. For sure there are specific exceptions, but even in these cases, conservation is probably best left for those with tons of experience. Other than soaking in pure acetone, I would strongly recommend that you not clean, wipe, or polish any of your coins.

If it is a variety coin, I would leave it alone. If it is a circulated coin, then I would soak it in mineral oil to help loosen the gunk around the coin. But a 100+ coin, I would not touch up. Who knows for sure what time will reveal about using even acetone? High dollar coins, I would leave them alone. When a coin is rubbed, the original finish it removed. If a coin is soaked in something acidic, then the top layer of the original surface is removed. Doing something dumb to a coin could reduce the value/future on a coin. So if you don't know what you are doing. leave them alone. Proof coins, don't even think about it.