Sebastian Body Double Thick-Extreme Treatment 5.1 Fl Oz. LOT OF 3 FREE SHIPPING! Sebastian Body Double Thick Extreme Treatment 5.1 oz Step 1 - Priming Lotion - After using Thick-In Shampoo and Conditioner, towel-dry hair. Saturate hair. Saturate hair with Priming Lotion and work through from roots to ends. Massage to ensure even penetration. Comb through and towel-dry the excess. Follow with Thickening Serum.