Nope, the sc is just tied/clipped to the sewn on loops of grosgrain webbing. Theres enough tension to lift the bottom of the bag snugly to the hammock. Probably a 3 foot length of 1/8" or 3/16" sc at each of the bag will be plenty. Adjust accordingly for your bag and hammock combo to get the right length. Or leave the sc long for use with other hammocks.
That was a mummy style bag.
Plenty of other folks had done this prior to my attempt and many after. Do a search for pod or sleeping bag and you'll find many references.