“Eventually” turned out to be thigh spinning/plying. In this technique plant fibers are spun and plied at the same time by rolling two strands knotted together and held by the left hand with one finger separating the two, down the thigh. Then the left hand releases and allows the two strands to ply back on themselves. Rinse, lather, repeat.
This is a very ancient technique for quickly creating rope or cording to be used immediately.
We tried it when my friends were here for spinning and it worked pretty well. The iris leaves were soaked a couple of hours and were still easy to work with 24 hours later. They were pretty easy to work with except for the parts at the base of the leaves which were thicker. Some of the leaves were split to make a finer cord (thinnest cord). The photo shows the results after the cords were dried. My joins were unsightly, but I was happy with the experiment. Then Cyndy found this video.
I tried the three ply, but it was much slower.