The old masters didn't have trouble with the cavesson alone...and I don't understand what you mean by camel headed. I work only in a cordeo or cavesson (I ride in a cavesson) and my horse is light, uphill and very responsive.
Some modern masters, such as Bent Branderup, also work without gadgets, doing beautiful work in the cavesson alone. The flexions of Baucher, tact in the hands and a light cavesson are all that are needed to achieve lightness, responsiveness, decontraction, willingness, lifting of the base of the neck and relaxation of the poll and readies the horse for the gymnastic exercises under saddle. The progressive classical gymnastics (lateral work) develops the topline, teaches the flexing of the haunches and readies the horse for high school.
If you watch the dvds of Philippe Karl or Buck Brannaman, you will find the means within your own two hands to help a horse through "evasions" and at the same time you develop a feel in your hands to the slightest nuances of the horse.
If all your horses become camel headed and strung out from working in a cavesson, then perhaps you can do a little study in the classical arts to remedy that. I don't mean to sound harsh, but this is not the forum to come and recommend side reins and gimmicks to reach the heart of a horse and gymnasiticize him in a physically and mentally sound way, again, within which the horse is a willing and eager participant. As a friend of mine once wisely said, "If I tied you, restrained you, then told you I meant you no harm, would you believe me?"