Work hard to get ET off the loo (4)
I believe the answer is:
toil
'work hard' is the definition.
(to toil is to do strenuous work)
'et off the loo' is the wordplay.
'off' suggests deleting specific letters ('off' can mean to remove).
'the loo' becomes 'toilet' (I've seen this in another clue).
'toilet' with 'et' removed is 'TOIL'.
'to get' acts as a link.
(Other definitions for toil that I've seen before include "Work really hard" , "Work hard, labour" , "Hard physical work" , "Drudgery" , "Work extremely hard" .)