How should I mix this green clay and how long do I leave the mask on?

Start by mixing a small amount of green clay powder with water in a non-metallic bowl, gradually adding liquid until you achieve a smooth, spreadable paste similar to thick yogurt. For areas like the back or T-zone where you might want a stronger effect, a slightly thicker consistency can work. Use your fingers or a clean brush to apply an even layer to clean, slightly damp skin.

Leave the mask on until it dries and begins to feel tight, which typically takes 10 to 15 minutes, but this can vary with room humidity and the thickness of your application. Because the clay is highly absorbent, it's important not to let it overdry completely, especially if you have sensitive or drier skin types — you can rinse it off as soon as it feels fully dry to the touch. Watch how your skin responds; if it feels uncomfortable or overly tight, shorten the time next use. Immediately after rinsing thoroughly with lukewarm water, follow with a suitable moisturizer to replenish skin hydration.