I remember this post from 15 years ago, which really got me started in the DIY device path. I wish I had pictures of what I made, which were modifications (improvements) of some stuff available here and online at the time.
I had jelqing, clamping and hanging incorporated at once, but ended up pulling something with the hanging and took a break. Those home depot clamps are excellent, just add some padding and get the right size so you get circular pressure, not just on the sides, you can adjust it how you like. I used good quality rubber and it helps if it has a pattern so it grips well during the clamp.
Happy clamping day!