i bought myself a tourniquet like that a couple weeks ago, given that the steps required to CTB seemed easy enough, but all i've managed to do with it is pop every blood vessel in my face. it is definitely possible to CTB with a military tourniquet, but the viability is, as always, heavily dependent on your ability to properly locate and close your carotid arteries.
i've gotten pretty good at locating my arteries, and i've felt the tingly/numb blacking out sensation quite a few times, but unconsciousness still eludes me -- my failure could just be more indicative of operator or object error rather than a mark against the method itself, though, so take that for what you will. given sufficient progress, i'll be sure to update folks on if/how i got it to work!