I have tried one time in earnest, I mean I really tried to stick it through. I used a hoodie, tied it into a loop around a shelf support thing above the couch, twisted it to make a loop, stuck my head through the loop and dangled my weight over the couch, putting as much pressure as I could on my neck (the sides particularly).
I was honestly unpleasantly surprised how long I was just sitting there, pressure building up in my face. I stopped, moved on to a doorknob, tried again, waited, didn't pass out. I was at it for a good half an hour Eventually I gave my completely because I was afraid my boyfriend might come back soon.
I decided that either I was doing it wrong (I was pretty drunk so the setup was sloppy), or that it's not as easy of a method as I previously thought. Good learning experience.
Honestly, I'm glad it didn't work. It would have been a really fucked up thing for my boyfriend to walk in on and I have always intended not to be one of those people who leave it to their loved ones to find and have to deal with my body.