Drano Max Gel Clog Remover is the #1 Selling Gel Drain Cleaner*. Drano thick drain unclogger formula pours right through standing water to cling to the toughest gunky clogs to blast them fast. *S.C. Johnson & Son, Inc. calculation based on GTC RMS Service for the Drain category for Latest 52 weeks ending March 31, 2024. Copyright © 2024, Nielsen Consumer LLC.