Quetzalcoatl
DEADY GUERRERO/DIRT COBAIN/GEORGE KUSH
Not as safe as the mountain air But...Wow, never heard of CelluCotton, thanks.
How safe is it to inhale?
http://en.wikipedia.org/wiki/Rayon
Rayon is a manufactured regenerated cellulose fiber. It is made from purified cellulose, primarily from wood pulp, which is chemically converted into a soluble compound. It is then dissolved and forced through a spinneret to produce filaments which are chemically solidified, resulting in synthetic fibers of nearly pure cellulose.
To put it in perspective, the wikipedia article for cotton says that the fibers of it are nearly pure cellulose. As long as no combustion occurs I think they're both fine. Like @Pipes mentioned it's been popular as a wicking material for ejuice for electronic cigarettes due to being extremely cheap ($20 gets you a few lifetimes' supply), being more resistant to dry hits (allowing more juice to vaporize from the wicks before the coils start combusting the wicks), and lacks the "cotton taste" from fresh wicks.