Snake oil, say, in no way unusual (7)
I believe the answer is:
nostrum
'snake oil say' is the definition.
(nostrum can mean a medicine sold by a fraud)
'no way unusual' is the wordplay.
'way' becomes 'st' (abbreviation for street).
'unusual' becomes 'rum' (I've seen this in other clues).
'no'+'st'+'rum'='NOSTRUM'
'in' acts as a link.
(Other definitions for nostrum that I've seen before include "secret potion" , "Patent medicine of highly questionable value" , "Ineffective medicine" , "answer to all problems!" , "Patent medicine with questionable efficacy" .)