This makes more sense than any other decode of 'watch the water' I've yet seen.
It's a good job it's a conspiracy theory too, or there'd be no plausible deniability.
After talking about the wonderful Dosas in Croydon over here, I've finally managed to take a picture of the heavenly ones they make at the Chennai Dosa and here it is. Inside that pancake like fold is a potato and lentil filling, while behind it are three little wells for putting the Dhal like soup, the white coconut chutney and a range of sauces including a chilli, tomato and a mango. All for dipping in. I'm also very fond of the basic metal beakers used for drinking London's finest tap water.