personally... i would "tip" the beaks... cut the end of the top beak off.. might bleed a bit.. stop the bleeding with "kwik stop" or silver nitrate sticks (get them from VET or groomer)
also feed them things you dont normally.. flake of hay,,, "four way" horse feed,, kitten food,, i have even bought 100 crickets from the reptile store, let the chickens chase them all over.. if they get out and live,, they are just crickets...
box of cheap cereal.. ect... be creative