Pungent cleanser (7)
I believe the answer is:
ammonia
'pungent cleanser' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for ammonia that I've seen before include "Gas; cleaning fluid" , "Pungent gas used in the manufacture of fertiliser" , "Pungent gas used in cleaning liquids" , "Gas released by smelling salts" , "Nitrogen-hydrogen gas" .)