That last link (the inner traditions one) didn't work so well, so I will show it here:

"Suddenly, the spirit of the mighty loa, Gran Bwa, takes hold of the Houngan who owns this peristyle. Gran Bwa is the great healer of the Vodou pantheon, associated with the Power of Nature and the forests. His movements tonight are so charged with energy that he seems to be flying as he spins around the room, leaping some four or five feet into the air, before coming to a stand still in front of the drums, which quickly pass into silence. He stands like a wild animal, in a half-crouch, as if ready to pounce, with arms on hips in a posture that signifies control and authority. He is swaying like the serpent of a snake charmer. If I have ever doubted the existence
of the spirits as separate entities with their own identity, the look on this possessed Houngan's face has cured me of that forever. This is a strong and furious loa, who must be placated quickly. The people are silent, awe-struck. Even the invited Mambos and Houngans seem concerned at this appearance. "Merde" -- "Shit" --someone behind me mutters, not very comfortingly.

"No one wants to approach this Gran Bwa, but they know that they must or who knows what might happen. So slowly, cautiously, laplas, the Houngan who is second in command, moves towards the possessed body of his religious leader. He lifts him up, helps him stand upright, then ties a blue scarf around his arm to signify his possession. He hands Gran Bwa a machete, a symbol of his office, feeds him rum and lights a cigar for him. I am struck by the trust of these people in their spirits; even though this Gran Bwa looks wild, he must be given the machete and fed with rum; that is the way of this spirit and his will must be done. . . .

"There is a legend that Gran Bwa was once struck by lightening as a punishment for some crime, and his face was so distorted and disfigured that his mouth is now pushed to one side. When he drinks through his ear, Gran Bwa is actually drinking through his disfigured mouth and, during possession, the Houngan's body changes physically so that his ear is transformed into a new mouth that can swallow the liquid offered to it. Now that Gran Bwa has been pacified and honoured by the people, he is ready to bestow favours. He pushes the machete deep into his arm to demonstrate that he has Power, that he cannot be hurt by weapons, that he is ready to heal the people. There is no blood."

--Haitian Journals, January 2000

The above is from the book: __Vodou Shaman: The Haitian Way of Healing and Power__
By (author) Ross Heaven