Wash out (5)
I believe the answer is:
rinse
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">wash out</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for rinse that I've seen before include "Cleanse in water" , "Swill out" , "Wash off surface dirt" , "Colour" , "Sluice" .)