Slit the frankfurters almost through lengthwise. Mix the pickle relish and prepared mustard together. Cut the cheddar cheese into 12 4 1/2 by 1/2-inch strips. Put one strip of cheddar cheese and about 2 tsp of the relish mixture into each frankfurter and set aside. Pan broil the bacon until partially cooked and still limp and drain. Starting at one end, securing the bacon with a wooden pick, wrap each frankfurter and secure the other end with a wooden pick also. Set the oven temperature to broil and arrange the bacon wrapped frankfurters on the broiler rack with the tops 3-inches below the heat source and broil until the bacon in cooked, turning once. Serve hot in the buns.
