Perception is the key to acceptance.
These last couple of weeks, I've started to ask owners/managers of places that I frequent if I can use my portable steamer in their places of business. I say it just like the title of this
thread, and every single one has said that yes it is fine. I also explain to the waiter/cashier/clerk that I asked the owner/manager if I could use my portable steamer, and that they already gave permission.
Once in a while, the person will ask what it's for, and I tell them that I used to be a smoker for a long time, and that smoking has wreaked havoc on my lungs. I also ask them if they've ever used a steamer at home to breathe better when they've had a cold or allergy problems. Almost everybody has used a store bought steamer sometime in their life, and knows that steam helps breathing in alot of cases.
Might be something worth trying in your neck of the woods!