The term CLEANSER CHEMICAL can be broken down into two crossword solutions: LYE (3 letters) and AMMONIA (7 letters). LYE is a type of alkali, which is a highly basic substance that is soluble in water. It is often used as a cleaning agent for removing grease and oils from surfaces. Ammonia is a colorless gas with a strong odor. It is also used as a cleaning agent, but it is more effective at removing dirt and stains than LYE. Both LYE and ammonia are commonly used in household cleaners.