Clean, as a deck (4)
I believe the answer is:
swab
'clean as a deck' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for swab that I've seen before include "Absorbent pad for cleansing or drying" , "Among others, Q-tip" , "Hospital cleaner" , "Cleaning implement" , "Mop up - uncouth fellow" .)