I use re-usable plastic ties to keep my two rear turnbuckles from twisting loose. I have Derringer clamps on the front, but they wont fit on the back (Fleet on 2005 Taco).
Jack, I did that on a TorkLift Super Hitch extension. The turnbuckles and chains gave lateral support to the hitch. It worked fine, but I had to replace the ties fairly frequently. My recollection is a month or two.
Here is what is used in many marine applications where loosening is not an option, but easy adjustability is required. There is a hole drilled in the stud of the turnbuckle. You can also loop a piece of wire through the holes.