I've never seen those kind of peepers. That's why they call these plastic ones "pinless". The chicken takes a few minutes to become accustomed to the slight discomfort of having prongs resting inside their beak holes, but the greater adjustment comes from not being able to see as they have before. They seem to focus on the device in front of their eyes for several minutes after they're first installed. I usually sit and hold my hen until she begins to see other things than the plastic in front of her eyes. This also prevents them from trying to scratch them off with their feet.
Sometimes I put them on and then have meal worms handy so I can immediately retrain their vision. They will not be able to see the worm if you hold it in front of them. You need to hold it below their crop so they can see it. It gives them incentive to refocus.
Another trick I employ is to take around four peeper devices and scatter them on the ground when I return the hen to the run. This gives the others a focus so they'll leave the new peeper wearer alone. Normally, they'll attack the strange device and try to get it off the wearer. The strangeness lasts just a few minutes, they examine the plastic things on the ground and then lose interest very quickly.
You need to be prepared for very intelligent hens to become so well adjusted to their peepers that they develop a work-around and resume feather picking as if they weren't wearing the peepers at all. That happened with Flo-the-serial-feather-picker. I got some bumpa-bits, a device that prevents the beak from closing down all the way, and it took all day for her to learn to eat with it. But Flo is so smart, she eventually defeated even that awful device and resumed her habit. Scroll back through this thread and you'll see photos of the bumpa bit.
This is why I was so disappointed when fermented feed didn't cure her. There really is nothing else to try.