Strike at residence to have the desired effect (3,4)
I believe the answer is:
hit home
'strike' is the definition.
(I know that hit home is a more specific form of the action strike)
'residence to have the desired effect' is the wordplay.
'residence' becomes 'home' (home is a kind of residence).
'to' says to put letters next to each other (I've seen this in other clues).
'have the desired effect' becomes 'hit' (I am not sure about this - if you are sure you should believe this answer much more).
'home' put after 'hit' is 'HIT HOME'.
'at' acts as a link.
Can you help me to learn more?
(Other definitions for hit home that I've seen before include "make impact" , "Strike a chord" .)