http://www.salitair.co.uk/
Someone mentioned salt pipes earlier in the thread. I took delivery of the above device earlier today and I'm looking forward to trying it later this evening.
I have read some positive online reviews and the link above includes a clip from ITV's 'This Morning' where it receives a positive review from their resident doctor, Dr. Chris Steele. After seeing that video I was keen to try it for myself and ordered mine straight away.
It occurs to me that rock salt should be easier than inhalers to come by should the SHTF. I plan to add some rock salt to my prepping supplies.
Btw, I bought from Amazon UK and got a slightly better deal than buying from the link. For £2 extra I got a second bottle of the refill salt included.
Hope you find this useful.