This is How I made a Hands Free Salt Pipe from a dust respirator.
I purchased a single cartridge respirator for $9US. It was the cheapest one I could find, and it is not comfortable. It doesn't seal that great either. Enough to prove my design. There are plenty of more expensive respirators, I bet they become more comfortable and function better as cost increases. This cheap one I bought, I would sure hate to wear it at a job, for hours a day, for filtering dust or paint. So what I learned today is that cheapest may not always be best.
I used a pair of SIDE CUTTERS to snip the plastic grille off of one side (the out side) of the dust filter cartridge. All that's in there is a piece of foam with a piece of gauze on either side. I left the gauze in the bottom of the cartridge and filled it with salt. I covered the salt with the second piece of gauze.
To reattach the grill to the front of the cartridge, I made a tool from a piece of wire and an xacto knife handle. Flatten one end of the wire so it fits in the handle. Heat the tip of the wire to red hot and use it to melt the plastic and weld each point. Not pretty. Don't breathe the fumes. They are nasty.
Then I put the "Salt Cartridge" into the respirator, adjusted the straps, and put it on. BAM! Salt Respirator. I make no claims as to it's effectivness at alleviating any respiratory distress, also not very comfortable.