You might be able to use flexible copper tubing, but if not you can visit the local hardware store and get tubing that is suitable for potable water and run some tap water through it for awhile to cleanse any residue it might have on the inner surfaces. The brief amount of time the water will be in contact with the tubing will not likely result in any accumultions of anything from the tubing.
Yes, nebulizing would likely be a good idea. If the cough lingers or worsens, add some lobelia to the CS (five parts CS and one part lobelia) and seriously consider getting some of the great Chinese herbal formula ClearLungs. When I was down in Utopia and the chemtrails were heavy, more than once everyone came down with respiratory bugs that we could not seem to beat, even with the wonderful CS (which kep it from getting too bad, but it kept lingering), until we added the ClearLungs.
All the best, and you are quite welcome - helping others is what we are here for.
Have great 2010!