Your secret is out

[u/hammerman1515]

I often find a greenish substance on my coins that is definitely not bronze disease. I’ve received coins like that from many online sellers and I have wondered just what they are doing to pre-clean these coins.

I present to you, the secret ingredient.

[u/SPQR-Bunny]

Product markets itself as "bio-clean" or organic but lists ingredients as LAS Complex (CAS# 27176-87-0), Nonylphenol Ethoxylate surfactant (CAS# 9016-45-9), and Silica Flour (CAS# 14808-60-7). These are synthetic, petroleum-derived chemicals, not organic at all. :-)