Dear Ouidad: i! It’s been said that mineral oil causes build up on the hair. How can I remove it, since I’ve been using some products that contains mineral oil? A: Wash your hair with a gentle deep cleansing shampoo (such as Water Works Clarifying Shampoo) which helps remove product build up as well as chlorine, hard water and mineral build up. Try to only use products containing mineral oil on dry hair as a finishing product. Use small amounts and work from the ends up (staying 1 inch away from the scalp).