There is another site which I cant find that recommends a few cups of clay straight into the bath water. Be prepared to then bucket the water out first and scrape up the used clay from the bottom of the bath. It will definately plug the drain.
The other day I mixed the Bentonite into a paste and put a thick layer over my face and neck. I sat watching tv for an hour with it on, and a spray bottle of water to keep it from drying. I then washed it off. The next day, a wart on my face that had been there for months (and I had booked an appointment to have it checked out as it was growing) - just fell off, like a dry peice of skin.