In a small glass bowl, combine clay, charcoal powder, apple cider vinegar and tea tree oil. Stir to combine. If the mixture is too dry, add a few drops of water at a time until desired consistency is reached.
Apply mask to clean face, spreading in an even layer. Wash hands and rinse out glass bowl.
Leave mask on for 10 minutes. Rinse mask off with warm water and a washcloth. If you have trouble getting rid of the color, apply this DIY Makeup Remover with a cotton pad to stained spots.