If I were to wipe the film off of a coin with a micro fiber cloth, would that be considered "cleaning"?
That might ruin your coin, I wouldn't do it. Show a pic of the coin, maybe we can help you once we see the problem.
If the coin has no grit or other debris on the surface, wiping should be undetectable. If it is undetectable, the coins hasn't been "cleaned"
Microfiber cloth is a plastic cloth and is a remarkably useful tool. Because it is a plastic cloth, it does scratch surfaces slightly.... I learned this lesson the hard way when I had to replace eyeglasses that I wiped with microfiber several times a day for a year. It was like I was looking through a fog. The worse they got, the more I wiped with the microfiber cloth I kept in my pocket..... I would keep microfiber and coins in separate rooms myself.
A microfiber cloth can leave hairline scratches on your coin. They could hurt the coin and lower its value. Soak it an industrial acetone as that won’t hurt the coin. Do not try fingernail polish remover. The will trace coin surface apart.
No to microfiber. Just give it a bath in industrial Acetone from The Home Depot, for example. Do the dipsy do!
If I need to "clean" a coin, I wash my hands good and give a gentle rub under running tap water, and then soak in acetone. If there is a stubborn piece of gunk, I use a soft plastic dental floss pick and carefully try to remove it. If that doesn't work, I leave it be.
I would also suggest that you practice on pocket change first. As mentioned if you post a picture of the coin I am sure someone can suggest something to try.
In contrast, I've been washing my glasses daily with detergent and running water, then drying them with plain old facial tissues - and after several years, they're still scratch- and haze-free. I think the biggest risk is dry-wiping them, dragging grit across them. (I did scratch one pair by drying them with commercial brown paper towels.) But eyeglass lenses are HARDER than coins, and if I did the same thing to a coin, I would expect it to get hairlines. So I don't do that.
I stopped buying expensive sunglasses years ago. Too easy to either break or lose them. I noticed that the cheap sunglasses with UV and polarized work great until you clean them then that protection just rubs off. Still, I can buy a new pair that will last a year at 20 bucks vs paying $300 for the real McCoys and plastic is a lot lighter than glass.
I think that is a safe bet. I remember when I got the coin of a lifetime, I was scared to touch it. It went straight to PCGS in the same safeflip it came in, I was scared to touch it. It came back MS67.
