Clay masks usually leave skin cleaner and worse. This one is cut with squalane and 4% niacinamide so it draws out congestion without taking the barrier down with it, and it is formulated to stay pliable rather than cracking - a cracked clay mask is a mask that has started pulling water out of your skin.
Montmorillonite from Auvergne does the absorbing, 1% salicylic acid works inside the pore, and glycerin keeps the finish soft. In a 12-week user trial of 76 volunteers using it twice weekly, 81% reported fewer visible blackheads across the nose and chin. Ten minutes is the full dose; there is nothing to gain from leaving it on longer.