Kokonuts...
The trolls I have been useing are Vance's Ball Trolls. They are 4' long, and I use 2 in tandem. I run them off the ball, and attach my release clip above on the rigger wire. I then let out line so my dodger is 2' in back of the trolls, and running 4' above. Running this close to the ball is only effective when your at least 40' down in my opinion. Any farther up in the water column I generally get back away from the boat, and shed the trolls.
I have heard of attaching the release clip to the ball trolls, but it seems to me that when you set up your rod and get a good arch, your pulling up on the trolls, thus restricting their rotation, vibration., and flash. I have heard success with this though... when the trolls are pulled up at an angle, the blades flutter more than spin, and that action can attract the koks too. When useing trolls this length, lower the downrigger ball slowly, and be aware of their location when they are raised up. I have used this set up for a few years now, and it really seems to get their attention.thumbsup