What do the professionals use to clean old coins?
I have some old coins that need cleaning, and I'm wondering what the professionals use to clean them. I want to know the specific tools or methods they employ to restore the coins' appearance.
Is it better to clean old coins or leave them dirty?
I'm wondering whether it's a good idea to clean old coins that have been collected over time, or if it's better to just leave them in their original, possibly dirty condition.