[snowtire]

Spiff, thanks for the idea. I looked around online and found it. It's called the KD Tools Back-Tap. I was actually envisioning this sort of thing as I was thinking about the problem, and it turns out someone has already made it. It is a split tap that goes down into the spark plug hole, expands, and then is turned and backed out. It starts on the good inner threads and straightens the bad ones on the outside as it goes. Also, less possibility for dropping crud in the combustion chamber because it is backing out. I want one ASAP, so I had a local parts place order one for delivery tomorrow afternoon for a premium--the tool costs around $65 this way as opposed to $45 from Amazon (delivery not included). I am excited to try it...