According to the card, the required amount of clay is mixed with water in a 1:1 ratio and stirred thoroughly to a uniform mass. For a mask, the mass is applied to the skin of the face or body and rinsed off with warm water after 15-20 minutes. The card does not describe any other consistency.
General information (not a manufacturer's instruction): it is better to prepare the mixture right before applying it, and the mask should not be left until it dries out completely.