Girth = Porn. A big advantage while working girth with porn is the increased level of arousal which will already give you the best erection possible, combine that with the extra blood you pump in and you have over your natural maximum expansion, which is my personal and many others belief on how girth is increased.
Sexually enlightening my generation one pussy at a time(sometimes 2 ;) ).
Improvement, it is the goal of life's search-Carl "Reaper" Sheapards