The tying method is not too painful. The string only hurts when you are tying it tight. I sterilize the site, and then I wet the string in hydrogen peroxide to sterilize it. Be sure to tie a square knot (right over left; left over right). Once it dries, the knot is even tighter, and it did not even bother me. Maybe a little itch. However, you must apply Black Ointment or some other dying ointment to help it heal and not come back once the tag has dropped off.
Remember that dog's tails are often lopped off by the tying method.
Tying is less painful than snipping them off like the doctor did to me. She would snip and then cauterize them. So, I jumped twice. Remember that I was given no pain reliever.
Personally I have found that applying a tiny drop of either clove oil, cinnamon oil, or oregano burns, but then following that with a drop of castor oil soothes and heals the wound. Caution: those oils will burn and are not to be used near or on mucus areas such as the eyes.