I've just stumbled upon this SSILD method recently and I have tried it half a dozen times as a relaxation exercise. Wow, I have never used a method that zoned be out so fast. And you would think that when I put more effort into focusing on the cycles I would stay awake, but no, I just go deeper. I have tried this at bedtime, before meditating and for naps. I have yet to try it for WBTB, but I think I may have found my solution to insomnia when taking Galantamine.
I also plan to try it on its own for LD and will report back.