[lomax]

Josephine wrote an interesting vision to banish things through fire.She says that fire is a trasporter.A gate between worlds.

You light a candle,with the intention to use the flame as a door to somewhere.(in this case the void).
You close your eyes,and you see (what you want to banish) into the flame.Then you blow it into the void by using your breath.

You give form to what you want to banish,(maybe this black smoke you've mentioned),you see it into the fire,and you transfer it somewhere else.