The effects of the exposure of chlorine happens instantly. The degree of damage would depend on how much was chlorine present, where did it enter and how long was the exposure. Inhalation of the gas would cause tightness in the chest, bronchospasm, and noncardiogenic pulmonary edema. When ingested, it would damage the gastrointestinal tract. Exposure to the gas would irritate eye and the skin. Also, it would cause burns.
No, it is not a scientific claim. If a ghost hunter catches a voice on video like ghost hunters do you can either believe it or not. Ghosts are more of a i believe it you dont have to type of thing becasue they have not been scientifically proven to exist.