variation/Jelq

OK, jelqing regular just hasn’t been doing it for me dry or wet. So I have been doing a variation, for about 3 weeks, that really gives me a good expansion.

This is what I do.
Sit at the edge of a chair with 60%-90% erection
Overhand OK grip the base of the penis
Angle the penis straight down
Slide hand down the penis toward the head until you feel the expansion. depending on how erect your penis is it could be 1/4 to 3/4 the way up
I do fast 1-2 sec strokes and basically “milk” my penis as if you where milking a cow.
This is done with a tight grip, and most of the time I use my middle finger at the end to add a little more pressure. sometimes I hold the expansion for a few seconds before starting a new stoke.

After a while the blood really engorges my penis and I try to keep it engorged as much as possible.

Does any one do this, and is there possibility for injury?