Not sure off the top of my head
no pun intended. I dont really count the amount, rather the time spent. So if that helps, usually went for 15-20 mins. So yeah, two techniques here. One clamped and one clamped off in the pump. You could even do this without any device but your hands.
I'll be fully updating the head exercise soon. I've been doing a variation I have never seen before, its not reinventing the wheel, but it places the focus on the corona and in doing so you create depth to the ridges of the glans. That creates better friction around the vaginal opening and more pleasure for you.
Any questions, please ask. I'm keeping Mike in the loop on this because I'll illustrate it but run it by him first to see what he thinks. That'll be easier then me just explaining it with no graphics.