Use a mop (4)
I believe the answer is:
swab
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">use a mop</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for swab that I've seen before include "Absorbent surgical pad" , "Small piece of cotton used to cleanse a wound" , "Hospital cleaner" , "Pad used in surgery" , "Wound-cleaner" .)