What interesting information about her voicing of the demon in The Exorcist. I don't get why swallowing raw eggs would roughen the tone of someone's voice.
I once asked my brother that is a voice actor about such things as I often drank raw eggs in a glass. He said some people do such things for the gag reflex which if violent enough can damage one's vocal chords and allow for a vocal effect they might otherwise not be able to attain.