My guess would be that the idea behind fogging is to weigh down aerosol in the room. It has been well documented by scientists across the internet that COVID ae

My guess would be that the idea behind fogging is to weigh down aerosol in the room. It has been well documented by scientists across the internet that COVID aerosols could remain in a poorly-ventilated room for a number of hours, this is because scientific thinking from reputable sources has now moved from "aerosolised droplets" to "airborne" (hence the importance of high-quality masks and not some random piece of cloth cut off an old t-shirt). So it could be therefore argued that in the absence of other (more preferred) options, fogging is a decent last resort to try to combat stagnant COVID aerosol because it will weigh down and/or disperse and/or dilute stagnant areas of COVID. Of course it is well understood by now that the preferred means to combat COVID is high levels of ventilation (open windows) and filtration (HEPA filters). But this is not always possible to achieve in an ideal manner either due to building construction (sealed windows etc.) or climate (cold weather, windy days etc.). So it is quite possible that using fogging as a "plan B" should not be entirely disregarded. (Disclaimer: I am not a scientist, the above is a simplified summary of my understanding based on what I've read from reputable scientists)