This is not hard to do. You can see my stages of learning below. By #4 dog I am professional.
dogs of your choosing
fave dog slicin' knife
long drill bit, (or round skewer if you have things like that)
Carefully push drill directly down the center of the hot dog.
Keep the knife at the same angle as you slice thru to the drill bit, and roll the hot dog away from you as you continue down the length of the dog. (pics 1 & 2) May or may not take you a couple trys to get method of nice tight coil.
See that I boil the dogs! (pic 3) Microwaving does not produce satisfactory results, IMHO. Slide the dog off the bit and into the water. Kinda tricky to fish 'em out, I used a spatula. Straining would be clever, if you have a colander.