Purifying Cleansing Milk for Oily and Acne-Prone Skin. Lait S.R. by Biologique Recherche is a sebum-regulating cleansing milk formulated to purify, balance, and gently cleanse skin prone to excess oil, breakouts, and congestion. With botanical extracts and light hydrating agents, it removes impurities while respecting the skin’s natural barrier—ideal for combination, oily, and blemish-prone skin types.