If you want to eliminate details and make it darker than anything possible, soak it in olive oil.
The more research I do on cleaning this coin the less likely I feel there is a solution. The corrosion is pretty heavy and I realize now there is no hope to save any of the green patina AND get detail on the rest of the coin.
The dirt is pretty much all gone in the pictures and what is left is corrosion. I am going to try picking at it a little and see what happens but I may end up just leaving it alone.
Bummer.
Has anyone tried using those Andre's Pencils yet? Word on the street is that these things really work.
At this point I would even consider tumbling. This coin might not be as rough as it looks. Bronze holds to better than copper. It will never look new again, but getting it more readable isn't a bad thing.