Additionally, if the feet of both hens and cock-birds are properly cared for, they will survive much longer, avoiding crippling, loss of egg reduction and a bunch of things that a miserable chicken in chronic pain (much like humans) is open to.
Can you just use the same kind of trimmers that you use for dog's nails? I've got a couple girls with 5 toes that really need manicures on those 5th toes.