Torchies have developed much purer composition of their alcohol based organic fluids than any other known gloople, as well as a very effective way of using this quality. A torchie's outer skin is considerable more flame resistant than its cousins and indeed a consistent flow of flammable liquid through pores of this membrane. The torchie is able to trigger a sudden and voltile chain reaction in a gland on its surface which combusts and sheathes the organism in flames. Then, it simply splats onto his enemy, allowing the rest of its fluid body to ignite, resulting in a powerful explosion.
It seems that a Torchie eventually burns out, and cannot catch fire again spontaneously for a certain amount of time, requiring the impact with an external flame. A possible explanation is that, when the "ignition gland" is activated, the pores close and the resupply of flammable liquid coating is interrupted - this is to avoid an immediate explosion at the moment of ignition; also, the gland, unlike the rest of the membrane, seems not fireproof, and has to be regrown, which requires time.