As far as I have seen, they do not work in the way they should. Most patches say that if you put them on your feet over night, then when you awake they will be dirty- filled with toxins from in your body. I have only seen them collect dirt from the environment. No proof its from your body.
No. The manufacter adds dried vinegar to the patch so when your foot sweats the pad will turn brown. Making it seem as if it drew toxins from the body.
The Kinotakara brand worked really well. One time a bright red and a bright green spot appeared. They looked like the color of M&M's. I wasn't grossed out by the color so it wasn't aversion.
The other brand Verseo had no effect despite using them for well over a month.