Found some interesting information on bentonite clay. Comes out of the ground. One side of the platelet is positive and one side is negative. It attracts the metals in your body. It acts like a sponge when it gets wet. Either taken internally or externally on your skin it pulls out the metals from within your body and attaches to the clay.

basically once it becomes hydrated, the electrical and molecular components of the clay rapidly change and produce an "electrical charge".