Don't do this. Use the needles. Much safer and easier, you will cut your mouth open, I had naty experiences. I use the needles as a closer for my show, as it is a much more elegant and safe effect. Trust me. Besides, if you will do the razor blade swallowing you might take it and use a hammer to gently tap the razor blades, or you can just take the blades and start rubbing the sharp sides on a rock or something.