Masseuse uses extracts of shrub berries (6)
I believe the answer is:
rubber
'masseuse' is the definition.
Although both the answer and definition are singular nouns, I cannot see how they can define each other.
'extracts of shrub berries' is the wordplay.
'extracts of' indicates the answer is hidden within the clue (I've seen 'extract of' mean this (I've seen this in other clues)).
'RUBBER' can be found hidden inside 'shrub berries'.
'uses' is the link.
Can you help me to learn more?
(Other definitions for rubber that I've seen before include "It's made from latex sap" , "Elastic material" , "using many cards?" , "Boring, obsessive type" , "fetish?" .)