I had a pony that had the halter cutting into the side of her face, I literally had to cut it off her face. I let her head heal (took like 3 months) and fed her and groomed and worked with her until her face healed. After she was all healed up, she was NOT going to let you put a halter on her, no way! So, I stood at her stall door when they came into feed. The moment she saw me with the halter, she turned away from me. The minute she did that, I closed her stall door, and she missed a meal. (Now, mind you, she has constant access to water and hay and a big pasture). The next meal came up (they get fed three times a day) and I stood outside her stall, she came up, saw the halter, did an about face, and I shut her door. She missed another meal. That evening, she came up, edged closer to me, but when I moved towards her, she turned away, and I shut the door. This went on the same way the next day. By the evening of the next day, she was really wanting her sweet feed. She walked up to me, and while tense as a board, she let me approach her, holding the halter. Since she didn't move away, I patted her, watching for ANY turn away (that wudda meant the door being shut) but she didn't. I walked off (halter still on my shoulder) and let her enter and eat. Didn't take her long to figger it out, if she turned away from me once I quietly shut the door and left. Soon I was able to walk right up to her, carrying the halter. Once we got that far, then I worked on actually puttin it on her. She came up to me, I was standing at her shoulder petting her, but when I touched the halter on my shoulder to slide it down, she turned away. Door was shut and I left. She figgered it out quick, tho, and only missed 2 meals. Then, came the time, she stood there, let me pet her, let me slide the halter off my shoulder, and put her nose in it, and buckle it, and she didn't move away. I let her eat with her halter on, and took it off before she was let back outta the stall. She always had to put her halter on to eat after that, but she was never halter sour again. She was the most extreme case I have ever dealt with about the halter issue, but it is to be understood.
Sorry so long, but I wanted to show how food can definitely be used to influence the behavior of a horse, but NEVER would I starve or dehydrate a horse for any reason. They may miss a meal to get a point, but they would ALWAYS have access to hay and water, always.
Supposedly if a horse has a rearing problem, you fill a glass bottle (not a real thick one like a coke bottle, but a thin one) and when the horse rears, and is the topmost part of his rear, you bust the bottle on his head. From going up and hitting something in the blue, and the water dripping down is supposed to make them think it is their own blood, is supposed to stop a horse from rearing. I would never try it, I have much longer taking but more effiecient means of training a horse to not rear. But I have heard some swear by it. Seems to me you would not only have a rearer, but a headshy one at that.
Also, the tail is supposed to be tied with a slipknot around the horse's head, or so I heard, so when he puts his head down he chokes himself. Again, not a method I would ever try, I have learned other ways to deal with bucking as well (that was supposed to be for bucking, btw, when he puts his head down to buck he gets choked.)
I don't like any training method that will make a horse not want you around. Some of my methods are a tuff at first, but never do I use pain, and I barely use fear.
I have seen real, serious abuse called 'training,' and done by so-called professionals. They CAN get some immediate results, but still have dangerous or lethal long term outcomes......
Know thyself, know thy horse.