Will Acetone do the trick for this Caracalla?

[Amarmur]

I have this caracalla denarius which has a fairly ugly obverse. Can giving it an acetone bath help wash off the patina? How long should I dip it in for?The reverse looks nice. 

 

[John Conduitt]

No. Acetone removes organic residues.

[Amarmur]

10 minutes ago, John Conduitt said:

No. Acetone removes organic residues.

is there anything I can use to remove the unwanted grime?

[John Conduitt]

It depends what it is. If it's the toning that's gone patchy, you'd have to strip it and hope it retones better (which it might not). But that would probably involve stripping both sides. Some sort of acid, like lemon juice and water, might do it. But you risk ruining the coin, especially if you don't know what it is. You could experiment first with distilled water/acetone and a cotton bud.

[Romismatist]

I would use GunBlue by Outers. https://www.outers-guncare.com/products/chemicals/cleaners-degreasers.aspx

It's typically used for cleaning gun barrels but is really good at removing deposits on silver coins. It will darken the coin, but it can then be lightened by putting it in an aluminium pie plate filled with warm salt water. You can lighten the silver depending on how long you leave it in the water.