Well, only like the international standards are in metric units
not to mention nearly all technology currently being researched is in metric not imperial... i.e. nanotechnology. imperial units do not exist in nanotechnology. it is all done in nanometers. most likely because no one would want to mess with fractions with such large denominators...
most engineering and drafting classes state-side is still taught in metric rather than imperial... or at the very least both... personally i prefer metric units myself... far easier, and with my interest in nanotechnology... kinda necessary....
on topic-ish:
as far as water and molotovs goes, i believe the only use for water in a molotov would be useful would be a small amount of water in the bottom, with inflammable-liquid of choice floating on top of it to increase the spread of flames over a larger area. saltwater would likely be a viable substitute for standard water. the water would likely have little effect on the fire itself, being underneath the fuel, and would only cause the resulting fire, though larger in diameter, to burn for a shorter period of time as there would be less fuel in the bottle used.