Sigh.........
If only you'd all said he was right to be extremly worried, we could have all taken a sadistic pleasure in making a grown man sob..........
I don't drink it with ice, lemon and ginger ale, and perhaps some nice cheesy biscuits, but if it's meant to go in your mouth I reckon it can't do that much harm, and spitting is so vulgar.
Amongst all the hilarious comments may I suggest that your friend reads the directions on the bottle. One time my dentist recommended a mouthwash and before i used it, I read the directions on the bottle and it said that if it was accidentally swallowed, you should go to the doctor or straight to hospital. I was so freaked out by this that I didn't even use it.