Scented stuff from spa lasts, if sprinkled
I believe the answer is:
bath salts
'scented stuff' is the definition.
'spa lasts if sprinkled' is the wordplay.
'spa' becomes 'bath'.
'if sprinkled' indicates anagramming the letters (letters scattered or sprinkled around).
'lasts' with letters rearranged gives 'salts'.
'bath'+'salts'='BATH-SALTS'
'from' is the link.
(Other definitions for bath salts that I've seen before include "Perfumes" , "tip these into the water" .)