Not sure if this is an exercise that someone has already posted but anyway i was doing a uli at 50% erect and started to mix it up abit would this be any good?

Get about 50 - 60% erect do a uli then make a ok grip around the middle and squeeze, then bend your penis upwards so the tip of your penis is facing your belly.

Would this be good if so what part of the penis would it exercise?