Jug slings don't come up much and are tricky to tie. Most people need a book in front of them.
A fairly easy alternative is to have one end of a cord hitch to a 3 o'clock position on the cylinder, and the other end hitch to a 9 o'clock position.
A simple, firmly-gripping lengthwise hitch is four turns finished with a
Gnat Hitch. You just have to work the coils tight.
I have such a setup suspending a variably-loaded straight cylinder with no lip or flange.