Perceiving stench of sailors can be restorative (8,5)
I believe the answer is:
smelling salts
'be restorative' is the definition.
The definition and answer can be both substances as well as being singular nouns.
Maybe there's a link between them I don't understand?
'perceiving stench of sailors' is the wordplay.
I cannot quite see how this works, but
'perceiving' could be 'smelling' (smelling is a kind of perceiving) and 'smelling' is located in the answer.
'sailors' could be 'salts' (salt is a kind of sailor) and 'salts' is found within the answer.
No letters remain.
This may be the basis of the clue (or it may be nonsense).
'can' acts as a link.
Can you help me to learn more?
(Other definitions for smelling salts that I've seen before include "could bring you round" , "stimulant" , "Swooner revivers" , "Substance once used to bring you round" , "Preparation used to arouse consciousness" .)