We do not currently know of any antonyms for Molotov cocktail.
The noun Molotov cocktail is defined as:
A crudeincendiarybomb made from a glass bottle, either filled with a flammableliquid such as petroleum and supplied with a rag for a fuse that is lit just before being hurled, or filled with such a mix of flammable liquids that it ignites itself when it is smashed and its contents are exposed to air.