SMOOTH AGAIN RINSE:Smoothly does it – thanks to our targeted smoothing and refining conditioner SMOOTH.AGAIN.RINSE. Created to nourish and smooth thick, coarse hair using ion-based cationic technology, Keratin Proteins mimic the structure of hair’s natural proteins to seamlessly smooth and refine where needed the most. This hardworking smoothing conditioner also provides a layer of protection to help seal split ends, and reduces the appearance of frizz.