Director with right milk container (6)
I believe the answer is:
rudder
'director' is the definition.
(I've seen this before)
'with right milk container' is the wordplay.
'with' means one lot of letters go next to another.
'right' becomes 'r' (abbreviation).
'milk container' becomes 'udder' (I've seen this in another clue).
'r'+'udder' is 'RUDDER'.
(Other definitions for rudder that I've seen before include "Boat steering surface" , "Control surface on plane's tail" , "It is used to steer boat or plane" , "Piece of metal or wood for steering boat" , "Ship's steering plate" .)