We use a good quality snap loop stringer and just cut them over the side of the boat and drop them in the water. We have had up to 7 on at a time.
After 1/2 hour or so put them in the cooler.
I find that the biggest reason to bleed them is whiter meat and less bloody mess when cleaning them.
PS DON'T FORGET TO BRING YOUR FISH BACK IN THE BOAT BEFORE YOU MOVE!!!!