We remove the head, and insert a garden hose down through the neck into the body cavity. Take care not to enter the stomach, but place the hose just inside the skin. It's easier than it sounds.
Use a hose clamp to tighten the neck around the garden hose, and turn on the water. The turtles legs will straighten out, and you can see and hear the skin tear loose from the meat. Makes cleaning much easier.
