I've been collecting zip ties from my part time job for a while now whenever I find them discarded and usable, always figured I could tie my hands up better during hanging so I literally cannot get out of it.
I mean, if you're fine with something then I don't personally see an issue I guess. I still think there's plenty room for error. As much as I like to think zip ties would stop me as well, our bodies can be capable of a lot more than we realize until they're pushed to such a point that we see. I don't have experience yet to say how well zip ties would work either so this is just my two cents.
Another consideration would just be your circumstances too, since the more painful a method the more likely you'll make a lot of noise and flail around if you really cannot escape, thus if there's anyone around they'd most likely hear. I experimented years ago with plastic bags, it can be a torturous method for sure and gives you plenty of time to think and for SI to kick in, so just be aware it could get even more violent and loud, even if you restrained yourself.
In some ways too I just think, any method seems painful, not to mention mentally we're always in pain, aren't we? So perhaps we just need to know what pain we can stand ourselves and what we're okay with. And if we're okay with it, then it works for us personally. Best wishes whatever you do especially if you go such a painful route. I'd just say know what you're getting into as much as is possible and continue thinking it through.
Random mention, but your username would roughly translate to "lonely" right? My anime-learned Japanese is going :/