Why is it better to drink milk, rather than water, after eating spicy foods?!

The hot part of the food is in the chilli and is fat-based. this means it is insoluble in water and drinking water does not remove it. Milk has fat and the chilli dissolves here and moves on.

Betetr is to take some yoghurt eg as a lovely mint and yoghurt sauce - just like the Indians.

If you want to quell the spiciness of foods, you drink milk because the fat and calcium and clean your mouth of the capsaicin, the chemical compound that makes chilis hot. Capsaicin is not water soluble which means that you can drink water, but it will only further disburse the capsaicin and make it even more painful.

oil-based and water won't rinse them out of the mouth. ... Have a milky or yogurty drink. Milk contains casein, a lipophilic protein that .... So, just out of interest, why, if after eating spicy foods a person feels so ..... meaning rather than the droplet used by my mates, I ended up with about a teaspoon full.

The hot spice in chile peppers, like jalapenos and habaneros, are oil-soluble (dissolves in oil).
Milk contains fat so it helps soothe the tongue.
Water contains no fat.

The compounds in the spicy food that cause it to burn your mouth are simply spread around by water. They are neutralized by compounds in the milk.

milk neutralizes the spices whereas water doesn't.