I was wondering how many people have actually tried to make the party cheese salad. Only doing a quick search, but I only found one case on here where someone claims to have made it for a work potluck.
There's also this on reddit.
Also, the DeadwingDork video.
It's still probably what he's most infamous for. I kind of feel bad for Aunt Myrna. She seems nice enough.
I believe I've seen around ten or so videos making attempts at it. The two biggest things wrong with party cheese salad, and keep in mind I said "biggest" and not "only," is the consistency and Jack's way of handling ingredients.
The first is the consistency has been described in multiple videos as "cold vomit" or "hard vomit," generally some variation of "like vomit." It's the biggest hurdle to get over, but a handful of video creators actually stomach it because it's mostly a mental thing.
The second is that Jack's recipe is a little deceptive. Jack uses processed ingredients and measures by the packaging rather than by actual proportions, including ingredients that are harder to find preprepared. The biggest offender is the recipe's green pepper. He uses precut green pepper, so it's going to be more bland. A normal human being is going to just cut a fresh pepper themselves, so the taste is stronger, hence the common complaint that the whole recipe just tastes like a bell pepper somebody already chewed up. I'm not defending party cheese salad, because it tastes vile even when prepped "properly." If anything, the people using fresh pepper aren't doing it justice because it's supposed to taste worse.
I have a few theories about the recipe. The first is that Jack is just stupid and has ageusia while most likely mishearing the original recipe. The second is that he secretly hates it. If you pay attention to the video, he actually only takes one bite and spends and awful amount of time trying to stomach it. Curiously, the camera abruptly stops while he motions to take a second bite, the fork never reaching his mouth. He may have been trying to do the video out of respect for the geriatric he got the recipe from and the whole thing is an act, but this makes a massive assumption Jack is suddenly able to discern poor tasting food.
My final thought is Aunt Myrna may have been on her way out and decided her last interaction with Jack is trolling the living blob by giving him a terrible recipe and then pulling a "woe is me" routine to guilt him into actually making a video on it. A reoccurring theme in my thoughts for all of these is I desperately want to believe somebody knew this monstrosity was a bad idea at some point, but this particular idea is what I believe is most likely, because Jack genuinely fails in all matters culinary and I refuse to believe it's hereditary.