Uncertain, but I don't think so. Of course it would if you were barely touching your penis, and then increase the pressure to a light grip, but from light grip to vice grip; no. You can think of it as overstraining your muscles, which is never beneficial, but straining them on the other hand is(workout perspective). I think for most people increase in pressure=bad PI's, so I will stick to my medium pressured jelqs and enjoy my well-functioning penis
-UYN-
After a while just like gym workouts it's hard to take it to the next level. From flat bench to cable flys. Hand stretch to hangers. I'm shure the first times someone brought up the idea of hanger, guys were thinking I'll stick to my hand stretches and a well functioning penis. But bib starts talking about gaining 4 inchs and people start going WTF he gained more then I have total,(not me, but just saying).
Although I am a big consumer, as i type on my iPad, and talk on my I4. My PE tool box, now a gym bag, includes two captain wrenches 5 lb in plate weights, drift weights, ads, chopsticks, lube, water and silcon, now this jelqtools.com kit, oh and my x4 extender with dual comfort stapes. And a sh*t load of different therabands, ace wrap, tape, journal, two rice socks, one bought and one made. At the end of this month i'm going to measure up and we'll see if over buying will outporduce.