Could someone please explain to me how the *garrot* works....
Have no idea......
There are photos of the garrote at the website I mentioned above.
In this particular instance, from what I recall from reports, a wire of cord was wrapped around the victim's neck and elsewhere and the portion around the neck was tightened by the twisting of a piece of wood (possibly a paint brush handle remnant) drawing the wrapped cord tighter and tighter.
It is a sad state of the world that those of us with little interest in the details are still inundated with so mush coverage and accounts as to pick up such specifics, but there it is. The whole apparatus is a 'garrott." And "to garrott" means to strangle by wire or cord device.
I believe it is inserted into the rope, and then used to twist the rope, tighting it with each twist.
think of a large twist tie from a garbage bag, with each turn it gets slightly tighter. If you wanted to twist it down super tight you need something to help you do that like a pair needle nose pliers or something slid between the twists of the tie to make a handle so you could twist the tie easier and hold the twist so that it would not spin backwards causing the tension to release.