Dryer lint, pocket lint, the threds hanging around the hole in the knee of your jeans. I've used them all with my poor mans sparklite. I don't advise gun powder, but there are some slow burning ones out there, like the old string powders like cordite, we took some out of WWII .303 British rounds with a bullet puller. Experimented with them as fuses so the burn slow in the open air. You could soak cotton balls in kerosene or gasoline and allow to air dry fully or till they are just barely damp and store in an air tight container. Hope this helps.