Be sure to experiment with the planned uses BEFORE depending upon them. Find out how much (or little) and what size grains work the best for your applications. It would appear that you need more than a couple of grains to develop suitable heat for fire starting and then it also depends upon what you are mixing it with.

It is definitely best to relegate this scientific investigation to the outdoors. Not only does it stain rather well, when it gets hot, there are some rather ugly fumes emitted.