11 is supposed to be SW. 10 is PW.
Of course, the player doesn't have to be 'married' to the Rule of 12 if they use it.
For instance, there's one course in Georgia called Cateeched. Awesome greens, probably a 12-13 on the stimp. I can go to the practice green, hit a few chips using the Rule of 12 and can easily understand that I need to take less club than the Rule of 12 designates. How much less? Well, see what happens on the practice green. If anything, the Rule of 12 is a good way to understand the speed of the greens before you go out and play.
As Brian said in the video where he had a 6-iron going a little long and a 7-iron going a little short on the chip. Try to figure out the other things like the green speed, slope of the green, etc.
I don't think the Rule of 12 is such an analytical thing...although it helps. I think the big key is that if you can trust it, the landing spot is a lot closer than if you are going to use your typical wedge chip and spin is far less of a factor so you don't have to worry about hitting your spot and it checking up on you as often.
But, I do think you need to practice this. When I first tried it I had success, but then shortly after had some struggles with it. So I had to practice with it to work out some of the kinks and figure out some of the pitfalls. In fact, part of it was that I had been pitching and chipping with the wedges for so long, I wasn't used to chipping with say an 8-iron. I needed to practice that for a bit (although not too long) to get that stuff down.
I won't say it's cut and dry the better way to do it. When I think of the all-time great chippers and pitchers of the ball I think of Mickelson, Paul Runyan, Raymond Floyd, Langer and Hubert Green.
Floyd and Langer used a variety of different clubs pitching and chipping the ball, although I don't know if they subscribed to the Rule of 12. Runyan essentially invented the Rule of 12. Green used basically his SW for all shots. Mickelson used to use the SW or the LW, but now uses more of the Rule of 12 approach.
3JACK