Toast the sides of the buns on a grill or griddle with a little butter. Then grill hot dogs. Place a little mustard along the inside of each bun and put the hot dog inside. Line them up in a long casserole side by side. Top each one with a little celery salt,more mustard, sauerkraut (well drained). Top with cheese and green onions. bake at 350 degrees uncovered for about 15 minutes and serve.