The message "Your thirst has been quenched does not mean you are 100% hydrated. If you get a message that says your stomach is full then you are fully hydrated.

"drinks 4 cans of soda"

"dehydrated 5 minutes later"

:D hilarious answer @earcl.
Personally, I drink at least 2-3 cans after I haven't drank for quite some time, so that my character wouldn't ask after 1 min that he is stupidly thirsty, dunno if in reality I would ask again after I haven't drank for quite some time and then...after I have already drank few more bottles of water or something else...would I ask or want another bottle ? + Soda most likely is not sugar free, just like coca-cola, sprite and such, they make you want to drink more after you have tasted few mouths of it, but if you drink water, you could survive without whining that you are thirsty for longer period than drinking soda. I got lucky that I found refillable water bottle, and ponds are in each small/big town anyway, so I can refill water in any time, and just in case I have enough room for medic bag that contains water purifier, dunno how you can tell if water is poisoned, but I haven't been gone sick when drinking a lot of that pond water. I didn't had such problem. I had problem that I posted about pond water, that it is not giving me the effect as it should, but people answered that it gives, but it only takes about 20-30 times from pond for thirsty status to change.