Cleaner of Barnet Post Office wearing fake ring (7)
I believe the answer is:
shampoo
'cleaner of barnet' is the definition.
'shampoo' can be an answer for 'cleaner' (shampoo cleans hair). I am not certain of the 'of barnet' bit.
'post office wearing fake ring' is the wordplay.
'post office' becomes 'po' (abbreviation).
'wearing' is an insertion indicator.
'fake' becomes 'sham' (sham can mean fake or pretend).
'ring' becomes 'O' (letter resembling a ring).
'sham'+'o'='shamo'
'po' placed inside 'shamo' is 'SHAMPOO'.
Can you help me to learn more?
(Other definitions for shampoo that I've seen before include "16 21 [INDIAN IMPORT]" , "Liquid soap" , "Would Mao shop for this cleaner?" , "Hair-cleaner" , "Hotel freebie - Warren Beatty movie" .)