REN Clean Skincare Flash Rinse 1 Minute Facial. REN Flash Rinse 1 Minute Facial instantly reveals brighter, smoother, firmer looking skin with a potent shot of 10% vitamin C. This water-activated gel treatment mask revives dull skin while firming and plumping with Boswellic Acid, also known as nature's Botox. The complexion is instantly firmer, smoother, and brighter, paving the way for long-term improvement in skin elasticity and tone.. Vitamin C from Ascorbic Acid stimulates collagen synthesis, evens skin tone, and provides instant radiance to the skin. Boswellic Acid from Boswellia Serrata Bark relaxes facial muscles to smooth lines and wrinkles. Glycogen Magnesium from Marine Glucose Mineral boosts skin energy and radiance. 2.5 fl oz. Apply to cleansed face and neck, then dampen fingertips with water and massage again to activate the Vitamin C; leave for 1 minute then rinse thoroughly. Use every 3 days or as skin sensitivity permits. RENR-WU37. 5060389240430.