I hate to be a pain, but I think I'm about to be. Sorry in advance.
Salt water will evaporate, but a bit slower than freshwater. So, if your goal was to add humidity to the air with salt water, the salt will slow that process down. (but not prevent it)
The salt would give the water something to bond to other than itself and is less likely to evaporate. Also, as the salt water slowly evaporates, the concentration of salt increases, further slowing the evaporation process.
I think you would be better off with plain water to add humidity to the air.
Also, after evaporation, the vast bulk of the salt would be left behind as a residue in your bowl. This is the principle behind the production of sea-salt. The cheeses would not pick up a lot of salt from the process of evaporation.
I would say that if you wanted to reduce unwanted molds, or add flavor, I would simply wash the rinds with a rag that is damp from salt brine .
Just my 2 cents.