Start of much work for cleaner (3)
I believe the answer is:
mop
'cleaner' is the definition.
(something which 'cleans')
'start of much work' is the wordplay.
'start of' suggests taking the first letters.
'work' becomes 'op' (abbreviation for opus).
The first letter of 'much' is 'm'.
'm'+'op'='MOP'
'for' is the link.
(Other definitions for mop that I've seen before include "Instrument for cleaning" , "Hair, unkempt" , "Polish" , "Floor cleaner" , "Clean; mass of hair" .)