when going full-
package at high Hg's I can feel the 'stretch' at a lower point...kind of in my 'taint' region.
The main reason I started pumping this way was due to frustration in keeping my testicles out of the pump when I increased the prussure w/the VacuVin...they'd always get sucked-in. I tried tying them back, then manually holding them while increasing the pressure, but I finally gave-in. Then it occured to me that the space my testicles were occupying in the
cylinder could aid in my focus on length, so I just kept at it (until MOS came-out w/the
MityVac and I opted for the more 'slender' 2 1/2" tube to limit any girth expansion)
Anyway, I have had zero ill-effects pumping this way