they are put through lines wrapped that are wrapped around the chicken line. They put the ball into the line and that acts to keep them stable out on the wire and not washed off the boat.
The chicken line runs from the transom to the bow tang then under the tramp attached to a bungee. The lines are attached to the chicken line by a prusik knot that tightens under pressure but can be slid around when it is loose. I did it this way for a race last year on my 6.0 and it saved me and Robi's butt. I am not sure what the intellectual lineage of that set up is but I got the info from Jake.