He lists his total routine at about 40 minutes per day, with a 5 on 2 off schedule. Hopefully he stops by, because I am wondering how he manages to pull his finger off that release valve hole at that pressure. I have to admit, I am tempted to try this some day when I have enough privacy to hook up an industrial air pump to my penis. But I also have to remind, it’s generally considered safe to keep pumping pressure below 10” Hg.
You have provided a good summary. You also stressed the key safety points (a) use a cylinder that is not much larger in diameter than your penis (b) drill a small hole in the end of the cylinder so it is easy to release pressure instantly (c) add cushioning to the bottom of the cylinder and leave a mat of pubic hair so the skin is less irritated.
I drilled a 1/8”mm hole in the cylinder. At full vacuum the force on my thump to release the pressure is negligible about 0.2 pound force. Tiny hole equals tiny force. Depending on how much space there is in the cylinder there is plenty of time to control the pressure build up using the thumb as the release.
My current cylinder is 2.5” diameter so the force involved there is about 68 pound force at the limit of my single stage pump - big hole gives big force.
I have a workshop and have the pump under the bench. Pump is noisy when close up and exposed but the bench muffles the noise and noise does not travel beyond the workshop.
If you try you should rightly be apprehensive the first time as I was and even using a smaller tube the force is significant. Seat the cylinder against the pubic bone before closing the sealing port.
I use a water based lubricant to start with but it will dry out after a few minutes. I then use vaseline on the cushion and inside the cylinder. I lube twice with vaseline during a session.
Even after 30 minutes I get fluid build up. There is no point going beyond 30 to 40 minutes because the fluid build up reduces the girth stretch anyhow. The various cylinders I have used have not been large enough to allow a doughnut to form.
If you keep going till the glans starts to sting then you are getting close to pulling a blister. It is something to avoid because a blister will likely take a week or more to heal.
Lately I have been contracting one of the pelvic floor muscles when I release the pressure and keep contracted until the pressure increases. This seems a faster way to get at the limit of my stretch.
Once your cylinder no longer fits on your erect penis it is time to go up in size if you want more girth. Note though that I do not start a session with an erection. The bigger the cylinder the bigger the force of course.
I still do manual stretching however overall I think that this short duration, on-off high pressure method is less traumatic than aggressive stretching and squeezing.
If I stick with the routine I can gain about 1/4” in length every 2 months. In reality it is about 1” a year because it is not possible to stay with the routine week in week out. My current cylinder is 10” long. When I fill that I will stop. Actual unpumped length then will be about 9.5” bone pressed.