The Fumigation Spell is a spell used to vanquish endothermals and their eggs.
In Bug a Boo, the Charmed Ones used this spell to vanquish a colony of Cicada Demons. However, as the effect of the spell was slow, the queen, Lainey, began to heat up the room in an attempt to kill everyone along with her. She was ultimately vanquished along with her colony when Macy Vaughn crushed her to death with heavy machinery.
Mist of magic, death unfurls. Clouds of poison, rise and swirl. Use our power, from thy breath. And vanquish these vermin to death. And vanquish these vermin to death!