I once took my roo to a building site (more of an interior renovation site) with me. He was great, followed me around everywhere, made sure the pipes were straight and even helped to hold down the bubblewrap I was taping to the radiators. Perfect little site foreman
He even perched on my OH's toolbox handle and left him a gift amongst the screwdrivers
i didn't say they weren't trainable in general, just not housetrainable
you'll never have a 100% spotless floor, that's all. chickens are totally trainable within reason, i know a lot of animal trainers actually learn clicker training and targeting techniques using chickens.