hey, so i did that lol. and i failed obviously. i tried it with a razor blade and were only able to cut my right arm open because i became really shaky and weren´t able to hold the blade with my other hand and cut straight. it is really difficult to get deep enough. i hit the main artery but after a while the blood gets thicker and won´t flow out anymore so you have to cut again and again and again. to even get this deep i hade to make multiple cuts in the same wound and it can be mentally really hard to get this far. but as i was then laying there and cutting again and again to get to blood flowing, my si became too strong and i had really strong physical symptoms. i was shaking, exteremly thirsty, sweated like crazy and was so full of fear. i was in a closed unit at the time so i was able to ask my roommate to call the nurses because i did something stupid. i think it´s really hard to ctb from this method. it´s not even the pain, but it just makes you physicallly sick to see your arm open. then the clotting and all of that... i would really advise you not to try this.