I'm really happy to hear you gave that knot a try and it worked out for you, but I forgot to mention one thing to beware of. If you pull them together like the knot is intended to end up (as in the animation), you most likely won't be able to separate them again or untie it either, for that matter!
The guy who hunts deer with me borrowed my binoculars to look at a deer we were watching and slipped the neck cord over his sweatshirt hood, but to do that he extended the length to where the knots were jammed tightly together. I had tightened my knots with pliers just like you did too, but I had also trimmed the cord ends real short and burned them besides! Needless to say, I had to cut the old neckstrap off and make a new one.
Is that a miniature Doberman? It looks a lot like my wife's cousin's pooch.