I’ve never really looked into it. I do neti with salt water regularly, and recommend, and same with steam inhalations - simple bowl w/boiling water and usually EOs like eucalyptus or breathing blends (I make a good one). You could tell me about them - breathing in steam from salty water?
No. It's dry - no moisture. Basically you're breathing in micro-crystals and negative ions. Apparently the air dragging over the salt crystals makes tiny crystals release. There is some real science on the efficacy as well, but not much. Mostly anecdotal evidence. Obviously this is with high quality Himalayan salt. The science says it can decrease mucus viscosity some. That's all kids of beneficial for a number of ailments. And we of course know salt wreaks havoc on microbial varmints.
I think you would find the stories of the healing salt caves quite interesting. There are even resorts set up in old salt mines:
This one looks swank.
https://healingsaltcaves.com