Hard jelqs are more prone to injury. The first time I jelqed I was totally erect, I used too much pressure, and the result was blood coming out of my urethra.
Hard jelqs are possible to do without injury for me because my penis has been conditioned by years of brutal routines, beginners shouldn’t attempt it. I don’t recommend jelqing, though I got some results from it in the beginning. Penis pumping is so easy and I’ve never been injured by 20 minutes every other day at 5 inHg. I wish I had started with pumping and never did jelqing or clamping now.
Keeping the penis semi flaccid is a matter of stopping when it becomes hard until it becomes semi flaccid. Gradually you will be able to jelq without getting a full erection.
Having a full erection is a good thing when pumping.
If you do decide to do pumping, I would avoid pumping over 20 minutes because while it gives you a little more temporary size than 20 minutes, it seems to impede growth. I tried pumping for 1 hour every other day at 7 inHg for months and got no length gains at all, but 20 minutes every other day at 5 inHg has produced reliable gradual gains over time.
Not everyone agrees about this, but I find a rigged aquarium pump to be better than a hand pump. Regardless of which you use, you should have a gauge to see what vacuum pressure you’re at.
I don’t really notice any benefit from using a heating pad on gains, but that may be because my penis has been through so much. Most of the people here seem to recommend using a heating pad and it’s certainly more comfortable with heat.
Starting: 7"bplx5.2" 2017 (shrunk from disuse)(originally 8"bplx4.5", gained to 9"bplx6")
Current: 9.0"bplx6.125" 2020
Goal: 11.5"bplx7" 2021.