Workout completed. Very hard, but doable thanks to Regina's and Tracy's hand protection suggestions (gymnastics tape and cut-off socks). Here are the results:
12K = 250 swings
16K = 500 swings
20K = 250 swings
I mostly did sets of 100 swings at the beginning, and 50 swings towards the end, with a minute of rest between sets. I didn't know how many I'd do with each kettlebell, and in fact I started the workout thinking I'd only use the 12K and 16K, but about halfway through I decided to use my heaviest kettlebell. What I wanted was a starting point for a 1000 swing workout, and now I've got it, and I'm very happy about that!
Tim came in with the camera when I was maybe 600 or 700 swings into the workout. But I have to see the video before I can commit to posting it.
Time to get ready to head to the gymnastics meet!