AC Moore carries them. I buy regular or duck sized eggs. Unpainted is okay. Though they get dirty and washed, they don't last forever.I have BO, RIR, EE's and a Brahma. Where do you get the wooden eggs? I have golf balls in mine right now.
I think it deters egg eating but can't be sure. I think many broken eggs are due to soft shells as layer feed does not have enough calcium.