For a fantasy effect of fire-cracker, we've used a flash pot and the actor mimed throwing something, setting the flash pot off a split second later, which was triggered by a violinist who made a 'screach' on the violin as she set it off. We've also had the actor mime throwing something, and used a 'Party Popper' (found at Wal-Mart) off stage for the sound. We've also used flash paper. It's really a great effect. Just use a glow plug to ignite it, and have the actor toss it. If done right, it's safe and will burn up before it touches the ground. We've also used real fire-crackers. (The kind you throw on the ground hard to make them go off-not the ones you light.) We lay down a some fire proof lining, and a metal sheet on top, and just throw them on the sheet, which is then pulled offstage. We've never used the firecrackers you light, but we did to a comic bomb once. It was a bowling ball that was painted with black fire resistant spray, and then gaff-taped some flash string to it. That worked well. Hope it helped.