PLEASE don't do this. A friend of mine had done it a few times and was getting confident in the process. Once I was watching him, the bottle broke into tiny pieces and went straight into his hand. He had around 30 pieces of shattered glass that managed their back several centimeters deep inside. I still remember calling emergency and waving hands when they arrived so that they saw us. My friend came back a few days after with his hand wrapped in band after a pretty awful night in hospital. Pretty stupid idea if you ask me. Don't do it. Remember one hand is one half of your text editor...