I am careful to clip each side separately, along the side and not just across the split. I am nervous about cutting too far and causing it to bleed, so I only clip a little away. I need to find the tube of Super Glue that hasn't stuck itself shut so I can try and glue the split part together. I did this once but had difficulty. The hen kept moving & jerking her head around, I feared getting the glue on her tongue, or gluing my fingers to her beak, or gluing her beak shut.
I wonder if something like suture strips or even a thin strip of duct tape, wound around the end of just the top beak, would help keep it together long enough to heal? I'm going to make more effort to immobilize the bird first before working on her, wrap her well with a towel and put a sock over her head with just her beak poking out a hole, and have a couple of the kids help hold & soothe her so I can get a good grip on her problem.