The metal part, yes.

However, the feet have the most sweat pores and they permit the most ionic activity in and out of the body short of the lungs or intestines.

Also, who is going to stand still with a hand on the faucet for hours on end every day to achieve any significant results?

The action is cumulative over time. The effects literally have to propogate or diffuse throughout your system just like food.

A simple touch won't do anything reall except discharge built up static electricity from the skin surface.