Cenospheres As Diffusion Beads?

http://en.wikipedia.org/wiki/Cenosphere

They have titanium/ceramic/other types of cenosphere beads that are quite a bit more attractive than the gel or glass beads being used. Although I have never used diffusion beads I was using cenospheres in another unrelated application and thought they may work out quite well for this.

They seem to be nearly microscopic. I doubt they would fare well in an application where one may potentially inhale them.

+2 points for creativity tho.