I think if you larkshead the fixed eye of the whoopies to the loop, it will stop the waterflow. I have been sleeping in a JH for four years now, I just ran the fixed eye of my whoopies through the channel and then the adjustable end through the eye and cinched it down. Works great, have not had water issues at all. Been that way for a couple of years. Just some ideas. I use whoopies and straps with great success.
I thought about doing this as well. Does this technique cinch the channel much?