Completely horrifying. I so sincerely hope nobody does this. It’s beyond words awful. It would be illegal where I am. In many countries it’s not legal to perform medical procedures on animals unless you are a trained professional. People can of course still do illegal things, it must be brought to the attention of the authorities before any action can be taken.
If this were a good method, vets would use it instead of going to the trouble of putting the rabbit under and performing surgery, especially on rabbits, a species that’s known to be particularly sensitive to full anesthesia. It think it’d be painful for the rabbit. It means cutting off the blood supply to body parts and there must be a risk of gangrene, septicaemia and death.
I added a warning to the title of this thread. I also made the link un-clickable, just so no one inadvertently clicks on it. This is not a pleasant topic to discuss, but because other people could find this horrible DIY-tip just like you did, and I feel it’s important to say how deeply inappropriate this method is.