They are not effective because I will do them while dreaming but they don't induce lucidity. If I can breathe through my closed nose, I'll just tell myself it wasn't all the way closed. I always have an excuse instead of becoming lucid. I have overcome come this by imagining and feeling that I do recognize that I'm dreaming while doing a RC while awake. It's obviously not necessary for everyone. Stephen Laberge does recommend something similar when doing RCs.