- Eliminate dryness and frizz instantly with RUSK® Thermal Alcohol-Free Serum. It’s a highly concentrated serum that smoothes and seals the hair’s cuticle, eliminating dryness and frizziness instantly. Ideal before or after blow-drying, it immediately creates silky, soft and healthy-looking hair. Perfect for color-treated hair or chemically treated hair. The unique combination of ingredients transforms dry, dull, damaged hair into smooth, silky hair with incredible shine and helps eliminate frizz and dryness. Perfect primer for any thermal styling tool, protecting from heat stress caused by daily use of heat appliances. Ideal for use on wet or dry hair. To use before blow-drying, apply a small amount to hair and style as desired. As a finishing tool, apply a small amount to dry hair and distribute evenly for instant smooth shine.