This seems like overkill to me, but Lamont is speaking very highly of this method. I personally rewatch movies extremely rarely, and the number of movies that I have seen more than once is very small, so the idea of watching one movie 50 times is rather nauseating.
I do, however, concur that re-consuming A/V media in an L2 is beneficial to me, as I noticed that I tend to struggle with correctly interpreting grammar the first time around.
I feel like 3-5 times would be best as you get to rematch and understand new parts without it becoming mind-numbing.