I don't think you can actually hurt yourself doing this unless you are the kind of guy who applies a lot of pressure. Don't.
You know how you're supposed to make sure the top of your double edge razor is tightly closed before shaving? You only need to try this once, very carefully, just so you know how it feels and you'll never forget it.
Loosen the knob a bit so the blade is not held rigidly in the razor head. Take a short, delicate stroke across your lathered beard. Feel that chatter? Hear the sound the edge makes on skin and whiskers? It's creepy but that's why you always make sure your blade is securely locked in place.
I received this education myself this morning. No knicks but I kept thinking, why is this so uncomfortable? I didn't figure it out till I rinsed the razor and noticed the doors were sort of flapping around.
david boise ID