I haven't tried this, but I could absolutely see this working for me as well. I've noticed that my visual imagination gets much more vivid just as I'm drifting off to sleep, so I have in the past tried to gently nudge that along by jumping between visual thoughts. It did work fairly well, but I also never had enough trouble sleeping to hone the technique or quantify its effectiveness.
Sometimes I have hypnagogic hallucinations of people talking, sometimes I can't understand the words, but it's nice because then I know that I'm falling asleep.
I get the same thing, but I've found that I can understand the words if I focus on them and try to understand them, though the problem is that as soon as I do I become more awake and it takes time to get back in to the hypnagogic state again after that, so I usually don't bother.
