Would this be a beneficial back workout? 2 reps every minute for 50 minute straights.

Its working for Doug. I mean, he is 100% natural

Good for the ego, I guess. It is obvious that guy has lot of strength and spare time, but why to do this? Mainly because he can. There is one Finnish dude competing in classic bodybuilding, skinny tall guy, and he love to do stupid shit like this. He have done four hour leg training session, one hour set of hack squat etc. utterly stupid things, and he still look like a broomstick. I find it quite hard to respect something like that. On the other hand, there were this old gym in Helsinki at the top floor of the old building. There were some old school bodybuilders training there, and because there wasn't room to do lunges, they take 100- 130 lb barbells with straps, went downstairs by the lift, and walk 8 floors back up with the weights = 1 set. That was a part of their training, no big fuzz about it, just a normal day in the office. People do silly things like that, others for gaining muscles, and others for gathering some respect from stupid's.