I have not used snappers for bait that way but I have used mullet close to that size and the trick I use is to form a piece of aluminum (chain link fence ties) with a small loop at one end just small enough to fit in the mouth. Pass it through the body and out the annal cavity. At this point attach the leader loop that is attached to a hook of what ever size you are using and pull it through the body and hook the hook into the tail area somewhere where it will not be seen too well. then attach the leader to your line by whatever means you are using and you have a pretty good way of hooking those that like to bite the tail.
I have been using this method for a while now and it works very well.
Happy Catching
Paul