Wash with elbow grease (5)
I believe the answer is:
scrub
'wash with elbow grease' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for scrub that I've seen before include "insignificant type" , "Vegetation consisting of stunted trees or bushes" , "Wash the stunted shrub?" , "Brush, in two senses" , "something in the garden?" .)