There's 1 correct and 121 feasible responses. We have checked our databases and feel the answer is LYE which was last viewed in the The Guardian Brief crossword. Only use chemical drain cleaners as a last vacation resort for seriously clogged drains. With recurring use, this chemical cocktail can try https://list-of-alkaline-solution64661.blogzet.com/indicators-on-what-cleaners-are-alkaline-you-should-know-43873988