Safe and effective or vice versa?

Hey all, I found an image supposedly helpful in lucid dreaming. My question is, though, is it really at all safe? Even so, is it effective in achieving lucidity? I say this because I haven't heard of exactly pleasant experiences with it.

For example, one who tried this felt like his limbs where slowly disjointing and detaching from his body before floating away when he tried this. Another felt like they got restless leg syndrome afterwards. I myself don't even like being paralyzed like this.

Has anyone tried this, is it safe and effective? Pros/Cons?

You're not too smart, are you?

That thumbnail is way too small to be read, but i found the source online. The method being described here is Wake Induced Lucid Dreaming. To answer your question, yes, it is perfectly safe. Any sensations you get while in sleep paralysis will only stay with you in sleep paralysis. Nothing bad is happening to your real body, no matter how realistic it may seem. And remember, to abort from SP you can try changing your breathing pattern dramatically and that should wake you up.