Account's what fall guy accepts in case of accessory getting special treatment (8,7)
I believe the answer is:
aversion therapy
'special treatment' is the definition.
'account's what fall guy accepts in case of accessory' is the wordplay.
'account' becomes 'version' (version is a kind of account**).
'what fall guy accepts' becomes 'therap' (someone blamed for something 'takes the rap').
'in' indicates putting letters inside.
'case of' means to remove the middle letters (outsides of).
'accessory' with its middle taken out is 'ay'.
'version'+'therap'='versiontherap'
'versiontherap' going within 'ay' is 'AVERSION THERAPY'.
'getting' is the link.
(Other definitions for aversion therapy that I've seen before include "Medical treatment" , "addict's treatment" , "Behaviour modification technique" , "Type of treatment" .)