Umbilical tapes from the OR work really well too, plus some come with a little foil tab that makes threading it between the ring and the finger really easy. Just wrap to compress, lube, and pull! One thing we did find out- if the ring has those little nubs on the inside that help keep it from spinning and is tight enough to need this trick, you are better off just cutting it off. We didn't realize a patient had these on his ring, and when we took it off (fortunately after he was already anesthetized), the nubs caused some pretty nasty damage to his finger. I now make it my routine that when we have a patient with a ring that won't come off to ask them if it has these nubs before trying the removal trick. And if your patient is destined for surgery and it's not absolutely imperative to take it off beforehand, this can be pretty painful so being asleep is also a good idea.
It takes longer to get on but I like waxed dental floss as well, although umbilical tape is what I see commonly used. The "string trick" is actually well enough established that you'll find it in UpToDate.
When my wedding rings were fitting tightly due to pregnancy, my MD suggested the same method to remove them should the need arise. That baby will be 20 this summer! An age old trick that's been around much longer than youtube!!
I saw them do the "string trick" on an episode of Emergency (with Roy DeSoto and Johnny Gage) back in the early 1970s!
(Yes, someone actually called the paramedics b/c of a stuck ring... b/c if the husband got back and saw that the employee was wearing his wife's wedding ring, the husband would go ballistic and kill them both!)