That is more of their dishonesty, LostGeneration. They say that he and his apostles DID use it hundreds of times. But they have no proof. They can only say "evidently" or "likely". They don't understand the TRUE meaning of the word "name". I've said it before (like many before me), when a cop says "Stop in the name of the law" he does NOT referring to an actual name. Our name is our power or authority. This is shown by the question given to Peter and John in Acts 4:7. When Jesus says he made Gods name known, he was not referring to the tetragrammeton. He was saying that he was showing that true salvation only came through God.This is shown in John 5:43.
Whether you believe in God or not, that is what Jesus was saying. Their interpretation that Jesus made his Fathers name known by telling everyone that his name was Jehovah is simply wrong according to scripture.