Save that for last. The idea was watching their egress points rendered ineffective one by one would persuade them to surrender.
I knew a guy years ago with a charming/scary fascination with fire. He told me of making more effective Molotov cocktails by using plastic jugs instead of glass. For one thing the container, with fingerprints, burns up with the fuel. For another the conical top acts as an amplifier of the impact, popping the cap and spraying fuel around.
He told me of a time he was hired to destroy a car, a high-performance special model. He lit a thermite bomb on the car’s hood, and true to the legend, it burned through the engine into the ground.
The guy has since died, so I needn’t worry about telling his stories.