AMC, I like all of your advice, but why do you say skip stretching totally?
I mean I guess since he is only going for girth and no length he doesn't need to stretch at all, but is there another reason behind you saying this?
Also if you do start clamping I certainly wouldn't go for 10 minutes, and I wouldn't even put a minimum time to do it either. Just a max time.
For example, for the very first time you do it, say you don't want to go for more than 4 minutes at a time. So on your first set you feel OK for the whole four minutes, so you take it off at the 4 minute mark, then on the second set after 3 minutes you start to feel some fatigue, so you go ahead and take it off even though you haven't reached 4 minutes. On the last set after only a minute and a half you feel fatigue, so you take it off.
at least that is how I do it. I don't put a minimum time on my clamping, just a max.