I have been pumping for over ten years and have gained over 1” in erect girth but not much in the length department and not much in the flaccid department; however, my flaccid is somewhat bigger than when I started, but I have yet to develop a meaningful hang. Bare in mind, some guys respond better than other guys.
A proper pumping routine should start slowly and build up to an effective program. I started out with a 10 minute morning session at 4 hg. of vacuum and added 2 minutes a week until i reached 20 minutes. I then increased the vacuum level to 5 hg. for another month or so at which point I added a second session in the evening. Several months later I added a 45 minute session at 4 hg. once a month. After four years, I had increased my girth by over 3/4”.