The advantages of hair oil Reduces frizz and moisturizes dry, damaged hair. Boosts the density of hair gives hair more luster Application: Apply twice a week for one to two hours if you have oily hair. Apply two to three times a week for one to two hours on dry hair. Guidelines: Massage the scalp with the oil for a minimum of five minutes. To guarantee penetration, massage the oil into the ends of the hair after applying it. You can choose to wear a plastic or heat cap over your hair. You can choose to leave the oil on your hair for one or two hours. After the treatment, give the hair a thorough wash.