It’s an interesting idea. Maybe you could set it up so that ANY pop machine has a setup like this, and instead of feeding it money, it could simply read a barcode on the back of the bottle and charge an account for your monthly “usage” of the pop machines. There has been some test marketing of Coke Machines which can communicate with a bluetooth phone and let you “order” a pop that way, and have it charged to an account.
One other thought, perhaps you could come up with a “sterilzation wand” that dips into the bottle sort of like a froth wand for an espresso machine. You would put the wand into the bottle, a steam and/or cleaning solution would be sprayed into it, then you dump out any dirty water, and finally, it gives it a “rinse” before you empty it a 2nd time and fill it up again.