The holocaust? Geez, somebody needs to get a life.
I've seen the movie about a zillion times (don't ask). First, it's a great opportunity for the filmmakers and techs to have some fun with lighting, camera angles, costumes, sets, scenery, textures, interesting-looking people, and so on. Film is, after all, a visual medium, and this is a visual feast. It really does get better and better each time you watch - just watch, don't think.
Second, the plot is a throw-away, just some bones to hang the interesting stuff on. Therefore, ignore the "plot". Instead, look at the little set-ups and interplay. They don't MEAN anything, but they're fascinating. Look at the details - like where people are sitting, or the shadows, or sweat, or the way they move their feet. The movie is really just a bunch of slightly-connected individual scenes. There's no need to read anything into the scenes. Just enjoy them.
Third, the most important thing about the movie isn't the movie itself, but the marketing. Barton Fink took a really strange "movie" and marketed the crap out of it, and came up with a winner. THAT's the real story, and it's a good one.
Armed with this information, have a few brews (or your relaxer of choice) and crank up the old DVD again, and enjoy the movie.
: edit: the holocaust is an interesting, important subject, and if you want to call a movie, or a can of Campbell's tomato soup, etc a metaphor for the holocaust go right ahead.