Kerastase Nutritive Masquintense Treatment, Thick, part of Kerastase products is an intensive treatment for very dry and coarse hair. Wash your hair with Bain Satin 1, 2 or 3. Apply 1 walnut size of product work into hair bit by bit. Leave for 5 to 10 minutes, hair may be covered by hot towel, add a little water to emulsify and rinse thoroughly.