I've seen several people here warn against using baking soda on silver coins. When I was much younger (40 years ago) I was a serious coin collector and remember reading somewhere (an "expert" source) that baking soda (sodium bicarbonate) was OK for circulated coins, and would not affect the value. I think it was recommended to use a pharmaceutical grade such as found in a drug store, not the Arm and Hammer brand. Does anyone else remember this? Maybe the experts have changed their minds.
I have recently used it on a war nickel which had mottled stains (nasty looking) and it came out fine, without looking "cleaned".
I have recently used it on a war nickel which had mottled stains (nasty looking) and it came out fine, without looking "cleaned".