I have only used the plain enzyma I've only used the straight enzymatic solution--not the all purpose--and can't vouch for the safety of other solutions.
Do you dissolve the tablets in water or saline solution? If I recall from using them in the past, the instructions said to use saline.
Just distilled water. The contact lens solutions have hydrogen peroxide and various salts and things.
I occasionally buy uncleaned coins. Usually poor quality coins, so usually bad results no matter what.
I bought a group of greek bronzes last week to play with. I put commercial baking soda in a short glass tumbler, added enough distilled water to make a paste, added a green coin, covered it with more of the thick paste solution and let it sit there until the soda had become dry and crusty. When I removed the coin, the area between the layers where the coin had been was green. I regularly conserve US/foreign coins so I plan to use some of the chemicals I have to soak an ancient. The old posting about removing BD was interesting. I'm going to be trying much cruder methods and hope to eventually produce outcomes such as ROC.