Completely spotless? (5)
I believe this is a double definition.
'completely' is the first definition.
(I've seen this before)
'spotless?' is the second definition.
(similar in meaning)
(Other definitions for clean that I've seen before include "Remove dirt or stain" , "thoroughly" , "Second part of 18" , "Uncontaminated" , "remove filth" .)
(Other definitions for clean as a whistle that I've seen before include "Deal with obstruction in pipe" , "with minimal mess" , "completely empty?" , "Totally innocent" , "Extremely free of dirt" .)