Shock collar. Ours are waterproof and really tough. Same idea as using a choke chain, except the shock collar gives you a 2,000 foot leash. You have to give a command that they already know, and if they ignore you you have about 3-5 seconds to correct them with the collar. A catahoula (or any cur dog) is real smart, they figure it out quick. Kenzie never gets shocked anymore, there is a "tone" on the collar too that you can use to get their attention. That's all she needs.
That's the only thing that's kept me from getting a shock collar. I really think Bailey is smart enough to realize once I take the shock collar off, she's free again.
I know what you mean about getting locked on though! The whole world shrinks down to them and that group of cattle.