Brush and clean thoroughly (5)
I believe the answer is:
scrub
I believe this is a double definition.
'brush' is the first definition.
(scrub brush is a kind of brush)
'clean thoroughly' is the second definition.
(I've seen this in another clue)
'and' is the link.
(Other definitions for scrub that I've seen before include "Cancel (informal)" , "insignificant type" , "stunted trees and brushwood" , "Cancel; clean vigorously" , "Scour - stunted trees" .)