I saw this online and had to try it. I used a 11/16 inch wrench, an old occularis plug, some theraband gold, some dankung tubing and of course a pouch. It is very fun to shoot and when I was starting out the few "fork" hits I got did nothing to the wrench.
Neat little project with a dollar invested, the wrench was 1 dollar at the thrift store, everything else I had on hand. Also the 11/16 inch wrench fit the plug I had better that a 3/4 inch wrench.