Thanks for the comments people!

So you just mix a quantity of the TiO2 into watered down white glue and paint it on, then burn it once it’s dried? Does the glue seize peel off later or do you leave it on?
Ryan,
Yep, just mix to about latex viscosity and paint on a good layer (I used just the tip of a foam brush).

Let it dry, I put it into my old food dehydrator to force the process. The PVA is water soluble so I let it soak in a water filled tub for a while then used a green "scrubby" sponge at the sink to remove the unfused paint. 
The TiO2 tends to settle out so the glue keeps it suspended while applying. I'd rather spray it on but need to play with the viscosity. You just need it applied thick enough so there is 100% coverage.