How to use Leave the mask on clean and dry face for 30-40 minutes. Remove the mask, discard it and massage the remaining serum into the skin with gentle circular motions. Do not rinse and follow with your daily skincare routine. Repeat the operation twice a week with a new mask (single-use mask). The Korean Smooch trick: it can be used cold by putting it in the fridge before use, for an astringent and toning effect!