Is this trick useful for some clipping:

"In the dining room, if you kill a zombie and, soon after, rest the pot of soup on the table, his body will not disappear."

Is the zombie body solid so you can push it around or maybe you can align the zombie near a wall before killing it?

in category "any% with glitch" is not need the dining. although I probably didn't understand your question

While I happen to be logged on here, let me answer this as well...

I think I can confirm off the top of my head that going to the dining room isn't beneficial to any% w/ glitches runs (as that's referred to over here). You don't get anything from that room and instead you can just sideways clip through the E3R1 door to E3R13 to get the lighter and maybe collision clip through to R11 and E5 (I haven't tested that BTW but it's explained in the Guide). Generally luring monsters to a different place to use them for clipping is super-slow because they move so slowly. And lastly, I can't imagine anywhere good to clip to from E3R12 anyhow (dining room).