And it wouldn't work. I don't think a lot of people would be comfortable sharing real complaints with the CEO who parachuted in for a single shift. It will probably end up being a bit of a Potemkin village situation. The shift will probably be filled up with the highest-motivated, most ass-kissing employees, whose focus will be keeping the CEO comfortable.
It would absolutely work in a sense. Of course the CEO will not get a real experience and of course no one will bring any real grievances to him. But the CEO will still get some exposure to day to day. It is still somewhat better than not doing it at all. It’s a good precedent to set and one can only hope more CEOs would follow
The CEO will quickly spot broken processes and inefficiencies. Ass kissing can't make up for business problems. Beyond that, by working in a different store, gets a feel on how generic the approach can be, and where they need local optimizations.
The only think you are taking out of the consideration is toxic lower management and asshole colleagues, but that's not something I'd expect the CEO to fix directly himself. If anything he is just bored of the ass kissers and good news shows, and wants to regain a feel of reality
They will quickly spot what they perceive to be broken processes and inefficiencies, but they don't have real experience of the actual work at that level to be able to safely move Chesterton's fence.