...exactly! You have to let the turnbuckle be the conductor in the simple green. Dont let the wire on your t/b in the fluid. Wrap the threads, dunk the majority of the rod and wait until you get the desired color. Take it out, flip the wire to the other end and dunk the remaining untreated part of your t/b.
The shade of color will vary by the length of time you soak it.

ps- I used alligator clips. Makes the job even more simple!