Cleansing solution (6)
I believe the answer is:
saline
'cleansing solution' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for saline that I've seen before include "Like contents of cellar" , "solution" , "Containing or tasting of salt" , "Intravenous feeding" , "Like seawater" .)