How It’s Done (Step 2): Swallowing Razor Blades
To perform the trick, the magician secrets three pre-prepared razors on a piece of thread within their mouth. This will hide in one cheek, and as they “swallow” each razor during the performance, they’ll hide them in their other cheek. Then it’s time to give the string a pull and reveal the pre-prepared second batch of razors that were hiding in their mouth all along.