If a book can have a clickbait title, this one does: Even the Stiffest People Can Do the Splits by Eiko. I bought it anyway, and I will give the program a try, with the following caveat: the book recommends doing the various stretching with bouncing, and the Mayo Clinic, for example says that is not a good idea here. Instead, I will be holding the stretches from 30 seconds to a minute, moving deeper if it seems like a good idea.
The program itself is minimal. There are two basic stretches you do daily for four weeks, plus an additional stretch unique to each week. The book, however, also includes, strangely, a short story about two workers in a Tokyo firm who use the program under the guidance of their director and Eiko herself, achieving not only the splits but professional success.
Bottom line: don’t buy it. Borrow it from the library or me. And please, don’t bounce.