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’m a big fan of comic operas/operettas, and repeat listening to particular shows has honestly helped my German quite a lot. It’s a pretty good way to train your neural network for grammar. And the music makes it a lot more fun to listen to the same things repeatedly!