I've heard people talk about chickens "sharpening" their beaks. In all the ten years of keeping chickens and observing them, it sure looks to me that when they drag their beaks back and forth across a surface, and that surface often includes my pants leg, top of my shoe, and my bare arm, they are not really sharpening their beaks so much as cleaning them of accumulated debris.
Even tiny chicks will wipe their beaks right after eating anything. This action never, in all my observation, occurs before eating. This leads me to believe this action is not honing their beaks or they would perform it before using their beaks, much as we sharpen a knife before using it, and we clean the knife after using it.