We have about 3/4 of our flock in peepers right now b/c they got stuck inside when we had a huge snow this winter and got into a bad pecking habit. I'm sorry that you bought the special pliers--they are just snap-ring pliers and can be had from any hardware store for $6.
Mine open wide enough, but not much more than "enough" without shooting off into space. The way I put the peepers on is to either get help, or to sit on a bale of shavings with the chicken between my legs and her wings pinned down. Slip the prongs of the pliers into the nose piece of the peepers from the top, so the handles are pointing up. Hold the chicken's head still with one hand, use the other hand with the pliers to put the peepers in one nostril then allow to close onto the other nostril. Wiggle them to make sure they're seated well. Then jump the heck out of the way b/c there's going to be a wild ball of chicken explode out of there to figure out how to get them off! They get used to them in less than half an hour.
While the peepers stick into the nostril, they don't pinch them shut. They may start out pinching them shut a little, but then once the hen wiggles them around and scratches at them, they're fine. Mine have been wearing them for three weeks, no problems.
Give the peepers another chance. They've saved three of my hens from the stewpot, b/c these hens were starting to take the feather plucking cannibalistic until the peepers were put on. I can't say enough good things about them.
