thank you for your ideas Marydean really appreciate it
BUT natural salt - like sea salt and himalayan salt have been known to produce an ionising affect when heated/dissolved in water etc. Ionisation is when the air becames charged with a higher number of negative not positive particles, and helps the air to be fresh and clean - like it is when you're at the beach or standing next to a waterfall. This is the principle behind salt lamps which are fairly popular these days.
From what I gather this is the same principle in the salt rooms. It is sea salt.
the salt rooms the ionised and saturated with a natural substance - a low concentration of curative highly dispersed aerosol of dry saline (salt).
The microclimate in our Salt Rooms is formed naturally, through convective diffusion from the salt walls combined with controlled temperature and humidity. This creates a hypo-bacterial and allergen-free air environment.
It may just be rubbish but reading a bit on the net I understand the theory behind it.
You can also buy salt inhalers for asthma and bronchial problems.