I know you should not clean a coin but if you can't see the details of the area your trying to look at. Soaking in hot tap water then a very soft brush. Would like everyone ones opinion
Due to the level of experience you have shown so far, it is best you don't do anything to your coins except to collect them, ask questions, and learn.
I would not brush a coin with anything unless it has no numismatic value in the first place.
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