They only tasted something strange when they awoke and realized that their bags had been rifled through. They were told by the train personnel that it was a common problem and that it was chloroform. It must be pretty potent because they ripped the buttons off my daughter's shirt and she felt nothing. She didn't believe this act was a sexual thing; just looking for a concealed pouch of money or something.
I wonder what the lethality of chloroform on top of sleep drugs would be. My guess is that Westerfield would not have molested the girl in her room, but removed her as quickly as possible. He may have planned to take her to a secluded location and have his way with her in a sleep-state. He may have planned to use a mask to conceal his identity and perhaps return the child. Perhaps he fed her additional barbituates [this is why it's important for the coroner to undertake a complete toxically and drug analysis in this case].
Westerfield is not a stupid man. He probably planned this thing out like a chess game.