Pumping Question

I have a question about milking the tube while pumping. From I understand and read, this action targets length. Do I pull on the tube and hold for specific time? Or is it done in short spurts?

I do it more for maintaining good circulation and helping to stay erect, not so much for length specifically. Do it in spurts, like you are trying to masturbate with the tube. The pressure should fluctuate 1 or 2”hg.