Boil water before you drink it. Water has evil spirits in it. They kill more people than anything else and will for the next two thousand years. Fire spirits chase the evil water spirits away -- you can tell because when they leave the water, it bubbles.
Pasteurization is likely to have a more visible effect. It will make the treated milk last longer before spoiling, which is a benefit that can be easily demonstrated. At a basic level, you just bring the temperature close to boiling but don't actually let it boil.
I think animal milk is sort of like the tomato: a wonderful, wonderful food which we think is long established and universally appreciated but which is, on historical and global scales, rounding error in terms of the human diet.
Widespread consumption of animal milk is like Things White People Like, 1850 AD Edition. (Really. Most milk sold at the time was buttermilk, a biproduct of the consumption of butter. The rest was considered agricultural waste and fed to hogs.)
If you take a quick glance around the world even today, consumption of liquid animal milk is still not the norm outside of the West. (Japan is changing but, even in the mid-twentieth century, "smells like butter" was one euphemism to refer to the Americans.)
