There was a notion, by some that an active ingredient was converted to an analogue of paracetamol. I doubt this was the curative agent.
Bismuth and Iodine aren't expensive, nor is formic
acid, what nation has the greatest deposits might
be a concern.
I remember using this and the results were almost
miraculous, there's no mention as to why this was
discontinued. Some hint that there were issues with
toxicity; without collaborative information.