Coke is not suspost to eat a tooth if in overnight. Constantly drinking pop will encourage cavities but my Dentist says it because it takes your slyvia about 20 minutes to nutralize the sugars, if you are constantly drinking it it cant ever be nutralized. You know the people, they always have an open drink by them and always taking a sip... thats what he was talking about.
Commerical beer is boiled for 60-90 minutes so any nasties in the water would be killed. Ever taste Old Style before its beer? I wouldnt let a dog drink that water. As bad as the beer is, it way better than the water.
Chlorine is bleach although Clorox may have other stuff in it-I dont know. Chlorine is pretty safe in low levels, city water used to use alot of it to kill bacteria (chlorimine is more common now). It will evaporate out if left in an open container. We have stored water at the hunting cabin for several months in 55 gallon barrels with bleach as preserative.
I think this goes without saying but when finished, recycle the containers when done, dont put them in the regular trash. When they are recycled, they are not cleaned and resold, they are ground up, remelted and made into new products.