A Molotov cocktail was a makeshift weapon. It used a fuse and alcohol to create a fiery explosion.
Scorby made a Molotov cocktail and threw it at a Krynoid. The explosion distracted it, allowing the Fourth Doctor to escape. (TV: The Seeds of Doom)
Ace was kicked out of the Girl Guides after she turned a summer camp's fairy marquee into a makeshift Molotov cocktail. (PROSE: Survival)