Was that in an S&M magazine or a medical text?

Personally, I wouldn't waste money to buy a high tech tourniquet. If you know the principles of how they work, and they are extremely simple, you can improvise one from so many different things.

Yeah, you're not going to be able to improvise a CAT scanner in an emergency, so go ahead and buy yourself one of those if you want. But a tourniquet should be easily doable with items that are probably within 10 feet of you at this very moment.

In my two decades as a paramedic on an ambulance, not once did I ever even remotely consider applying a tourniquet. Outside of a war zone, they are just not needed very often. Sure, you should learn how to create and use one, because there's a slim chance that you'll have to. But don't confuse the suggestion to learn how with thinking that you'll be using one frequently.