This is the very best way to re-patinate your over-cleaned/stripped AE ancient coins...at least if you want them to appear in their "original" state.
Just a 20-30 second wash in the liquid is all it takes. The solution can then be returned to the vial for further use. One 4 oz. flask will last you any number of uses.
The "Black" Darkener will give your coins a ebony-appearing patina, much like an well-toned silver/silvered coin.