To deal an effective blow, refuse to work in the house (6,4)
I believe the answer is:
strike home
'to deal an effective blow' is the definition.
(I've seen this before)
'refuse to work in the house' is the wordplay.
'refuse to work' becomes 'strike' (as in to go on strike).
'in the house' becomes 'home' (to be home is to be in your house).
'strike'+'home'='STRIKE HOME'
(Other definitions for strike home that I've seen before include "Hit the intended target" , "impact" , "Have an effect" , "Deal an effective blow" .)