I remember when the Bernie Madoff scandal was going down, some time after the trial (I may be wrong on exact times/dates) one of his sons used a dog leash to hang himself in his apartment. He successfully CTB'd.
Anyhow, as far as compression as means of ending one's life, it's certainly possible. I have these thick-ish elastic exercise bands from physical therapy, though I'm planning to use the 'night night' method when the time comes. That said, if one was thinking of using an elastic or stretch type dog leash or again, exercise bands like I mentioned above, the leash or bands would likely need to be wrapped around one's neck multiple times and I'm not certain how to secure them from slipping. It's worth researching.
