I had some old ones in zip lock bags this Sat. that were very ripe
I also bought some fresh 2 hours before crabbing. The stinky ones caught more crabs than fresh but you didn't want to leave the bag open. I like my necks to get a little smell but not green and rotton I don't unbait my trot line just rebait beside old neck. The old bait gets eaten in a couple hours anyways. I freeze my line on a hose reel.