The pinless peepers just pop right into place. We tried to deal with a certain breed that just kept picking until death and had to resort to the pinless peepers. Worked like a charm and it doesn't hinder their breeding, eating or daily routine.
I bought some for my RIR who was not being very nice to the newbies in the coop. She would get up on the roost and beat the crud out of the cockerals. By the time they arrived (it took over 2 weeks instead of the 2-3 days) everything had settled down and it wasn't an issue anymore.
But I will use them next time I integrate babies in the coop.