No what I am saying is if it is done intentionally to create the toning, it's being done by artificial means. An accidental use of those items would be someone knows they can cause and/or accelerate toning but forgot about that fact and used it anyway. Amateurs doing it, well you know they say about amateurs, they knew not what they were doing to begin with.
So you're saying that the key to a continuing supply of naturally-toned coins is a combination of ignorance (people don't know what causes it) and senility (people used to know, but forgot). I'm not finding this very edifying.