A great improv stove is possible, since perlite is freequently used in office pot plants - even in fake ones ! That's what the garden centre sell it for !

Other materials, including coarse sand, glass wool insulation could be used too.

I have used sand with alcohol, as well as kerosene and even diesel once. These are not nice fuels to use inside, but they will work.

I've only used the glass wool insulation with alcohol.

Thanks for the perlite /altoids idea Sue.