Cleaning? Think Twice

I have lost several old coins in detail from cleaning and I thought it important to post about another failure. I found this Buffalo yesterday and got the date, as you will see in the pic, then what was left after I used heated peroxide, a soft toothbrush and paste. My understanding was that the peroxide wasn't caustic to nickels. It DARNED sure is on old pennies, especially IHs.

If you find an old relic coin, consider taking pics before any cleaning. It wasn't a key date mind you but I found it sad to lose the details.