I use the Aztec Healing Clay from Whole Foods on my skin as a facial, it really cleared up my acne. I never thought about using it in my hair. It has many different uses you can even drink. I tried to drink it, not a good idea.
It comes in powder form and you mix it with water to form a mixture with a toothpaste like consistency. You can make it thicker or thinner it depends on how much water you add.
Here's some more info...
Bentonite Clay can absorb any toxic substances imaginable: impurities, harmful bacteria, poisons, pesticides, pathogens, parasites, etc. It does this without posing any nasty side effects in us, because as mentioned before, it can't be absorbed by us.
Bentonite can also be used externally, to treat skin problems and for detox baths. Some people have used Bentonite Clay to treat skin rashes with a lot of success. If you have skin eruptions such as acne, you should try applying Bentonite Clay on your skin, as it does a tremendous job of extracting/removing all the toxic matter buried inside your skin.
Bentonite can also be used in a detox bath, where we apply the Bentonite Clay around our body. It helps releases toxins out of our body, and it is a great routine to practice during colon cleansing.
Its very affordable I paid $6 or $7 for a large 1lb jar. A little goes a long way, I use it everyday and I still have plenty. I think my jar will last me a year!