Acne-Fighting Tea Tree Mask 1 TB bentonite clay 1-2 TB water 1 TB ground oats 4 drops tea tree essential oil Combine the bentonite clay and oats in a small bowl. (Please do not use a metal utensil or bowl when working with bentonite clay.) Add in enough water to make a spreadable paste. Add 4 drops of tea tree oil and stir. Apply to the face for 10-15 minutes. To remove the mask, wash your face with warm water and a washcloth.