Campaigner less refined without it (8)
I believe the answer is:
crusader
'campaigner' is the definition.
(eg someone on a moral crusade)
'less refined without it' is the wordplay.
'less refined' becomes 'cruder' (I've seen this in another clue).
'without' is an insertion indicator ('without' can be similar in meaning to 'outside').
'it' becomes 'sa' (old-fashioned abbreviation for sex appeal).
'cruder' enclosing 'sa' is 'CRUSADER'.
(Other definitions for crusader that I've seen before include "Religious campaigner" , "Warrior in a holy war" , "Vigorous campaigner" , "Christian warrior" , "Advocate for a cause - rude scar (anag)" .)