Fuel will remain on the bottom of the stove after the flames go out if house insulation is used. The material that I use is very dense and the fibers are verticle which is the way we want them to aid the capillary transfer of fuel from the bottom of the stove to the top. The density of the material holds the fuel tight and releases it in a somewhat controlled manner.
House insulation fibers are usually horizontal when manufactured and probably 1/3 the density of the material I use.