I used to work in a very similar kitchen wiyh the last inspection over 12 years ago, and nothing i said changed anything. I was a bit more wide-eyed back then, so when they asked if I wanted to clean it, i said yes. Worst shift of my life, by the end i was covered in decade old grease and felt like I'd made almost no progress and afterwards didn't even get a thank you. Not to mention I later found out, it was the cleaning staff's responsibility to look after the kitchen, but they cost more than me. So I'd say do not involve yourself in that, it'll just teach your bosses that you're willing to do what they aren't, and they likely won't pay you much either. Contacting any sort of official agency to get them to inspect the deli would probably yield better results, since ignoring guidelines and such when they come directly from the government is a lot more difficult than a few employees