Help How to block carotids?

[ascension]

I've been lurking on forum for a while and realized that NN suits me best, since I'm a bit afraid of hanging myself and don't have any place to do that anyway. I pressed my carotid arteries with my thumbs, and after 5 seconds my vision went dark, and after 10 seconds my body started shaking, but I don't know how to press them without using my thumbs. I tried using socks filled with rice, but they turned out to be too hard and too big (round) to effectively compress the carotids. I think I need something smaller but longer, like my thumb, to hit the carotid arteries precisely, and hold it with ratchet strap. I've been doing this while sitting, but when I tried doing it while lying on the couch, my carotid arteries shifted, making them harder to squeeze; it required more pressure. So I've found that sitting in a chair and resting my head on the table works well for me. But this shifts my carotids closer to adams apple and deeper, and to pinch it, I need something like a thumb. Would something triangular-shaped work, with the corner pressing against the carotid artery? Am I doing anything wrong? I'm thinking of ctb tomorrow morning