I do 1 on, 1 off and it works great for me. I do 300 jelqs and thanks to a kind forum member who actually sent me clamps from halfway across the world without charge or even me asking ( he kindly offered out of the blue),
3 x 4 minute clamping sessions, and man, this might not be the thread for it but clamping rules. It feels good, it LOOKS good, and it seems to work very well.
Take care.