So maybe the next case of post layover 'Delhi Belly' will be impossible to cure. That's just another reason to not go to India.

I've never considered bottled water optional in India. I would even go as far as making sure the bottled water is from outside the country (i.e. take it off the aircraft). No mixed drinks with ice, avoid salads and cold dishes and get the heck out of the country ASAP.

Too bad I have a BLR layover next month.....

FWIW, our Flight Surgeon once recommended that the bottled water be carbonated. Not that CO2 kills germs; it's just less likely to be local tap water in recycled bottles.