I don't think anyone has said they can always heal someone from long distance with only a first name, especially not in a way that someone else dictates.
I think they were saying that it can be done, but it won't always be done, and it does depend on a lot of factors, including the receptivity of the recipient, karma, and the will of the infinite.
Definition of a skeptic: A self appointed vigilante for the suppression of curiosity.