As far as the discoloration goes, I thought of a simple experiment I plan to try. I read several accounts of people saying that it is the sweat in your feet that reacts with the chemicals in the pad to cause the discoloration. I plan to set up a control where a pad is left out overnight. For the experiment, another pad will be sprayed with a saline solution (mimicing sweat). This should at least confirm or deny those specific claims.
I do agree that testing body chemistry before and after would provide the most satisfying results, but it's beyond my "lab in a basement" capabilities.
It would be great to see a formal study, but I suspect that most in the medical community regard these pads with enough suspicion to not warrant such an investigation.
