Wash with water (5)
I believe the answer is:
rinse
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">wash with water</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for rinse that I've seen before include "Sluice" , "Hair tint" , "Swill out" , "Mouth cleansing solution" , "Wash - siren (anag)" .)