Joe,
I have a symetrical Spinnaker on my Oday 22. It uses the eye on the front of the mast and into one of the base eyes of the spinnaker. It actually is what I would call a whisker pole, with a hook on one end that attaches to the mast and a pin type end on the opposite end that goes into one of the lower eyes of the spinnaker. I have used it, but don't run into the chance to often. I find that I use the whisker pole more on my jib for down wind sailing. I push the jib out one side and the main out the other side. This has proven to help when winds are light and there just doesn't seem to be enough wind.
Enjoy the spinnaker, they are lots of fun when you have the opportunity to use it.
Jim