Here is a simple setup I was using a while back for Static Progressive Stretching. I drilled a ¼’’ hole approximately 3’ above the mattress through a stud on the wall behind my bed. The length of chain is 3’ long. You could replace the turnbuckle with a spring loaded fish scale in order to apply dynamic tension instead.
I also wrapped a rice sock around my penis behind my hanger.
I enjoyed this as I was able to relax into the stretch while visualizing my penis getting longer. This was a nice break to all the hours I spent hanging while sitting at my desk.
Then (4.5 nbpel x 4.75 mseg)
Now (5.625 nbpel, x 5.25 mseg)