The version we use is common in North America - sporadically found and mined from the province of Alberta to the northern plains of Texas. Dr. Bernard Jensen, and other naturopaths, have recommended Bentonite for years as yet another vermifuge (parasite cleanser) and general detoxifier.
Its use among naturopaths is primarily internal. Unless otherwise recommended by your health care practitioner, you should stick to the one teaspoon/day protocol.