Drano® Liquid Clog Removers can unclog a drain fast. They contain chemicals that quickly dissolve hair, soap scum and gunk. You can use Drano® Liquid Clog Removers to unclog a kitchen sink, bathroom sink, shower or clogged bathtub, but DON'T use them in toilets.For clogged or slow-running drains, apply the product and let it work 15 minutes. For tough problems, allow 30 minutes.This product will NOT open a completely clogged toilet.). Do not use any other Drano® product in toilets. Drano® Kitchen Crystals Clog Remover generates heat that can cause the vitreous china in the toilet bowl to crack. Drano® Liquid Clog Remover and Drano® Max Gel Clog Remover do not contain microorganisms.