You people are going to laugh at this one. I don't do much residential wiring anymore, but when I did, I used a large wooden handled vegetable (potato) peeler, with one edge sharpened slightly to cut the jacket completely off once it was peeled open. It didn't take long to get fast at it with this tool. They last a very long time and you can replace it for under $3.00 at the grocery store. LOL
Matt