Combine water, witch hazel, and unflavored gelatin in a small, microwave-safe bowl and stir well.
Microwave in 15-second intervals until the mixture is warm and the gelatin dissolves when stirred.
Add the kaolin clay, coconut milk powder, and activated charcoal. Stir well.
Let the mask cool for a minute or two before applying it to your face. If you let it sit too long, the mask will firm up, but you can always bring it back to liquid by microwaving for a few seconds.
Wash and dry your face, then apply the mask in a thin layer using a clean, flat brush or your fingertips. Let sit for 10–15 minutes until it begins to peel off easily.
Peel the mask off, then wash your face with warm water and a washcloth to remove any remaining bits, and finish your skincare routine.