Washes with first class, non-fat premium soap (6)
I believe the answer is:
cleans
'washes' is the definition.
(I've seen this in another clue)
'with first class non-fat premium soap' is the wordplay.
'with' is an insertion indicator.
'first' becomes 'a' (first letter of the alphabet).
'class' becomes 'cl' (I've seen this in other clues).
'non fat premium soap' becomes 'ens' (I can't explain this - if you can you should give a lot more credence to this answer).
'cl'+'ens'='clens'
'a' put within 'clens' is 'CLEANS'.
Can you help me to learn more?
(Other definitions for cleans that I've seen before include "See 14" , "Washes, removes dirt" , "Tidies up" , "Valets" , "Washes, makes sanitary" .)