I heard of somebody doing this and did it a bit myself with a batch of chicks. They used the same stick/shovel every time and soon the chickens learned to run into the coop when they see that stick. It is a great idea!I gave a short answer, the long answer is that I trained mine to target sticks when they where younger. Ex. Follow the target stick = get treat. I tried shaping it into other tasks, such as "spin" but it did not go well.. they are chickens after all..
They also know to come when i yell "GIRLS!" and they definitely know the sound of the treat bag being opened
My goal is to train them to run into the coop on command for when I have to put them away early or i need them to retreat back to safe place b/c of predators