If I understand your title correctly. Is that a question about furling a symmetrical Spinnaker or an Asymmetrical spinnaker. Going with the Asymmetrical theory I use a Facnor continuous line furler on a bow sprit to deploy/retrieve a new custom gennaker on our 26. It's in the same link that jack gave above and works like a charm single handed, making furling from the cockpit as easy as he implied. I'm sure it could all scale up to fit your 38.
The load on the bow sprit was a challenge that we've overcome and the hardware is shockingly pricey (my wife calls it boat jewelry) but after it's said and done I'm satisfied with the ease and safety of using the sail solo. I usually hoist it at the beginning of the day if the weather is appropriate, leaving it furled, and simply deploy it when the mood strikes me. The Facnor video accurately shows how easy it deploys but you'd better be sitting down when you price the whole deal compared to a sock.
Good luck in your choice, mike