Extension cord blues

I made one of the boards with the screws in it this weekend after reading this post. I usually did it by securing the cord in a vise and just used a razor knife but as someone said you always end up cutting some strands. Anyhow I replaced the screw with a razor blade that I hammered into the wood block with just enough of the point inside the hole. That is the ticket for me. The wire just slit where the screw would skip and bunch up on the other side. I will try and post a picture later. It cut my time by at least two beers.
I also thought about a screw gun in reverse to untwist the wires. I just read that tip today. It would seem that the other end of the cord would have to be attached to some type of swivel.