Why not use a rope halter or other style of halter like some clinicians suggest instead of a proper bosal?
A rope halter or a hackamore/bosal, especially ones that don't fit well, can twist on the face without permitting a consistently repeatable signal. This not only confuses the transmission of communication, but also desensitizes the area over time. A leather halter can do the same, but in addition, they can be leaned against by the horse and/or the handler.
When using a halter, handlers often put them on horses and “see saw” up their noses into place. This is not only annoying to the horse, it also acts to desensitize the face which has an enormous amount of nerves. Halters should not be left hanging loosely, but should be of a proper size and adjusted to fit closely. They serve a specific purpose, but were never designed for advancing horsemanship.
An issue people don't think about:
Rope halters can can rotate and pull
the delicate hairs around the eyes.
NOTE: Thousands of horses are killed or maimed each year by hanging up with a halter. Leaving halters on growing colts can damage them permanently.
Protect and preserve your horse. Halters should always be removed when the horse is turned out or put away. If you can’t catch him, a halter will make little difference. Work on getting your horse to want to be with you and easy to catch.
Halters should be used as halters, not as fake bosals for the masses. Each piece of gear has a specific purpose, design use and function. By their very nature, halters cannot take the place of correctly made and adjusted bosals, nor add to the progression of the bridle work.
We may also use our lass ropes only for leading or tie a lead line (get down rope) with a bowline around our horses’ necks. Alternating between a halter, a lead and a lass rope keeps it fresh for horse and handler.
We do not encourage letting a horse drag a lead. This pulls on his face. It all adds up to desensitizing the area and feel we want to preserve for the hackamore and the bit. Joe Bruce says that he asks God (and the horses he came into contact with) for forgiveness for every lead he left dragging before he came to understand.
We do use a rope halter that has a certain amount of body to it so that it will remain open if a colt is trying to seek the right spot to put his head to cooperate. Contrary to the belief that softer is better, if the halter is too floppy and soft, it is harder for the horse, even a mature bridle horse, to feel and respond to. Too narrow and light? The halter can end up cutting him or tearing up your hands.
Rope halters are a readily available, cheap way to work with a large group of people and horses. They may be OK for a week or two with a colt, but any longer use definitely results in counterproductive time and effort---if your goal is a bridle horse. The term “hackamore” or “la jáquima” means halter or headstall, after all.
To have a chance at positive results in the making of a bridle horse, you must invest in correctly made authentic equipment, not imitations, no matter how fancy they “appear” to be. There are no cheap substitutes, only a waste of money and time. If we want to encourage a sensitive horse that is open and receptive to our communication for the long run, we should not betray his trust by confusing or creating discomfort for him. Well-made and maintained gear will pay back in results as well as in resale value.