I use it for my leg... my foot issues do not cause so much pain, and I have not tried it there. The PN in my feet is irritating but not terribly painful. I control burning (which is more common in summer) with Biofreeze gel.

I had a chart for placement of the electrodes, and I'll try to find it for you.
No, I don't use it with water, or mag.

It is best with 4 electrodes, and you put them A B B A in a square with the target in the middle.
The PTs at my rehab place said IFc is far superior to TENS etc. It supposedly actually heals.

If you want the website with placement locations, please confirm and I'll look it up for you. (if I still have it, or it is still open).