I love skull firecracker

If the firecracker hasn’t worked within 20 minutes of igniting it, immerse the firecracker in a tank of water for 24 hours and then bury it in the ground.

Product Warning:

No smoking! Danger of fire or particle damage. Protect from heat, hot surfaces, sparks, open fires and other ignition sources. Do not expose to grinding/shocks/friction.
Wear protective gloves / protective clothing / safety goggles.

In case of fire:

Clear the area. Due to danger of an explosion, retreat to a safe distance. DON’T PUT THE FIRE OUT if it reaches the explosives. Danger of explosion. Keep only in the original package. Remove the contents/packaging by handing over to an authorised person for disposal.