Brining them toughens them up so they last longer and also stay on the hook a bit better.
They lose no scent as the scent is in the brine. I've been fishing this salt water for over thirty years and plug cutting them before hand makes no difference. In fact I prefer it so I'm not cut plugging when the bite is on. Fish have a very small brain and when feeding in the salt they aren't real picky.
_________________________
"You learn more from losing than you do from winning." Lou Pinella