Here's a great trick for getting hot hide glue deep in to a tight crack.

The stopper inside an insulin syringe fits over the end of the StewMac glue syringe (maybe the same as a veterinarian syringe), so you can use it as a glue injector. Much easier to clean and maintain the StewMac syringe, and gives really good control to shoot glue into a tight crack. I wish I knew that years ago.

You'll want to puncture the center of the stopper. I have ended up cleaning out the hole with a drill bit maybe 1/16" or so?

Theses syringes disassemble nicely for cleaning, hold plenty of glue, and are easy to control. They come with different sizes of needles if you want them. It's also easy to get your syringe loaded up, then leave it in the glue pot to keep warm until you're ready to go. Very handy.