Ok so my horse wont tie in a wash rack. Ive tried and he pulls back til his lead snaps. On a really hot day, he'll stand and eat grass while i spray him but i can never shampoo him cause he'll walk off since i cant tie him. How do you teach a horse not to panic? He did get caught up in one when he was younger so im thinking this is why he acts up but he just refuses to stand still in a wash rack. How can i reboost his confidence in one of these?