Is it safe to drink out of a Windex bottle?
If you drink the cleaning product that comes in the bottle, then
no.
However, cleaning out the empty bottle with dish soap and water
thoroughly and refilling it with another substance, for instance,
water or blue Gatorade, then it should be safe. Still, your drink
may taste slightly like the cleaning product due to chemical
residue being left inside the bottle. There will not be nearly
enough residue to actually cause any harmful side-effects,
though.