Nonsense! While there may indeed be a "too out there to write a believable story" zone, there is not a "too out there to write an ENJOYABLE story" zone. You just have to couch it in terms that will tolerate the unbelievability. Farce, satire, science fiction or fantasy, lots of ways to take an unbelievable but H.O.T. story and make it work.
Yeah, there's actually a couple of sushi bars where I live that do those at least once a month and will do it on special occasions for a private party if you can rake up the cash.
Actually, I like the fruit platter idea better as it requires less prep work and is safer from a food serving standpoint (Also, you can shake things up by having a male model who takes a viagra beforehand and has a fruit pyramid built around his erection). I will admit when I was younger I found the idea sexier but really nowadays I would see the idea as just a background element for a story (setting up a hedonist's party or maybe just setting the atmosphere for a story).
I remember reading one (fictional) story about a woman did naked sushi. Mild humiliation but not exactly meant to be titilating. You could focus on the woman's nervousness and prep though (She has to remain perfectly still no matter what she hears (the models rarely ever have food (if meat is the feature) directly touching them so actually getting touched directly doesn't happen for the most part). Lots of cleaning and the model has to remain in a cool or even cold environment prior to the presentation so her body heat doesn't raise the temperature of the food too fast.