Hiya
It's never an easy task, especially if you've hatched them out yourself. As you, I cannot do the final task, my OH has to do it.
We have a dispatcher mounted on an old door-frame in an outbuilding, it's a very quick job - if you are holding the body, pull back slightly as you yank the dispatcher down - instant kill, though they do flap about for about a minute afterwards, we know this is only a nerve response - someone showed me this to be true by chopping-off the head of a cockeral & the body still thrashed about for over a minute afterwards.
My OH was full of bruises after dispatching 5 turkeys last Christmas.
Remember to adjust your dispatcher, depending on the size of chuck you are wanting to cull.