I always despatch/bleed immediately and then place my catch on ice.
Interesting question, what is it supposed to do?
I rinse almost everything in fresh as most of my cleaning is done at home. I'm talking blackfish, drummer, bream, kings, jews, mackerel, snapper, squid you name it I'll rinse it in fresh.
Interestingly I have a mate who is sure he can tell when fish/squid has been rinsed in fresh as it "spoils it". Soooooo...... i go to the effort of cleaning by the sea one day(king fillet & squid), rinsing in salt water only. Once home I prepare another fillet which had been left on the frame and another squid, both rinsed in fresh. He comes over for dinner and I fill him in as to what is going on and ask him to tell me which is which, he couldn't tell the difference and to be honest neither have I been able to.