Minutes if he uses the right techniques. But that's not allowed (just sayin'. We don't want this here). The regular way.... Hours. Let's assume the pages load really quickly (or he uses several tabs or something) and he only has to click the button manually, taking a second per post. 20 posts per page, plus one second to switch pages. So that's 13.818 seconds when this page is full. That's 3.8 hours. So let's round that reasonably and say that it will take him 4 hours if he is really fast. Edit: more reasonably I'd say it would be more than double the time. Still doable within less than a day.
The problem is I get nauseous if I scroll to quickly, especially if there are bright images involved. Alright here goes nothing
40 pages through, I may not be old enough to drive or drink but already I find beer jokes funny, I find gf jokes comical, and now want to eat more pizza as my beer belly expands. The corruption has begun, there is no turning back.
The White House is probably one of the last places I would want to be. There are no dam legos in that thing. Imagine how boring it would be.