Current measure in Soho upset cleaner (7)
I believe the answer is:
shampoo
'cleaner' is the definition.
(shampoo is a kind of cleaner)
'current measure in soho upset' is the wordplay.
'current measure' becomes 'amp' (short for ampere, unit of electrical current).
'in' is an insertion indicator.
'upset' indicates an anagram.
'soho' is an anagram of 'shoo'.
'amp' placed inside 'shoo' is 'SHAMPOO'.
(Other definitions for shampoo that I've seen before include "Hair or carpet cleaner" , "Soap for washing hair" , "Apply liquid to hair ..." , "Hair lotion" , "clean" .)