>Is the reason for kegeling while performing this exercise to help keep blood in the penis?
Pretty much but this is a held kegel not a series of kegels. My tourniquets are also pretty violent and efficient but adding the kegel still increases effectiveness.
>Still, I can’t get my shaft to balloon up at all. It pretty much just gets to maximum erection girth.
Then you not doing it effieciently.
What I look for is pretty much a 100% errection. I create the base grip loose (with an overhand ok), kegel and hold a couple of times and increase to tourniquet. This on its own inflates the girth. With the tourniquet in place I hold a kegel and then exclude blood from the glans, sometimes using the traditional technique but mostly now by simply squeezing a fist over the glans.
I often slip into a sadsak mod from here explouting the overhand ok. Remving the hand from the glans, leving the tourniquet in place and gadualy adding a finger at a time to the grip to push blood into the upper shaft and glans.
This is pretty intense and I have blown holes in blood vessels on three seperate occassions by pushing it too far.