I know not to clean coins, but I do experiment with some good candidates of low value. I've also had some successes. Coins that we're 63s, cracked, quickly dipped and resubmitted for 65s., for instance.
I dip really quickly and then thoroughly bathe in acetone. Pat and let dry. Recently, some cleaned coins have begun to show light brown spots quite a while later, like a month or more later. I think it's just because I didn't clean out my acetone bath enough and there were remnants of ezest in there. But, what does the forum think?
Many of my previously cleaned coins are fine, even in the long term. Recent batches have been the problem. That's why I think it's just impure acetone, but I wanted to get opinions.