Let's not forget about the Florida man that thought it would be cute to stick his pee pee in the Pool vacuum hose.
He had to be removed from the pool wall and the tube cut free from his penis by the fire dept.
BTW..I did this when I was a kid and it is VERY powerful and pulls VERY hard.
(Hydraulic negative pressure) You grow ultra fast, but its not the right way to do it.
The key to vacuum enlargement techniques is to use LOW vacuum over an extended period of time. The idea is to stretch the cells, and maintain adequate blood flow for cell division and growth over time.
Not saying that it couldn't work with a vacuum...but it's a less conventional method.
I guess if you can try it, let us know. Use LOTS of lube, and put a vacuum gage on the hose to see how much vacuum your pulling.
Beginners or advanced should not go over 5mm/hg of vacuum.