Never, never, never hook your chicken line to your harness. Ours attaches to the trapeze handle. It allows you to release out (unhook) as easily as if it were not there.

Jake:
I would argue that it is a safety device:
Racing: You will do anything to get maximum boat speed. That means that the crew will be out downwind in a breeze. They will be hooked to the trapeze to do this. If you stuff the bow the boat will stop or at the very least slow down fast. This will keep your crew from ending up somewhere around the cheese cutter front end of the boat.

Other than racing: If you do not send the crew out on the wire downwind you do not need it.

The Chicken line is only for downwind sailing on my boat.

Mary:
The line you are talking about is a combination of Chicken and Righting line. It will work (kind of) for a boat that does not require a crew to constantly mess with a spinnaker. It is really only in effect when on a reach. If you are going downwind on a non-spinnaker boat both bodies are on-board. It depends on the strength of the crew as the skipper will bang in the crew when the line is needed, then the crew is holding everyones weight.

Later,
Dan