I can see two cases where tu quoque arguments could have some utility:
if they make the recipient realize “hey, I’m doing it wrong too”, or
if they lead the recipient to explain her valid reason for what looks like a wrong behavior, which might either enlighten her accuser to see that his own behavior can’t be excused in this way, or enlighten the recipient herself into realizing that her excuse also excuses the accuser’s behavior.
I can see two cases where tu quoque arguments could have some utility:
if they make the recipient realize “hey, I’m doing it wrong too”, or
if they lead the recipient to explain her valid reason for what looks like a wrong behavior, which might either enlighten her accuser to see that his own behavior can’t be excused in this way, or enlighten the recipient herself into realizing that her excuse also excuses the accuser’s behavior.
This probably doesn’t happen often, though.