Ok well it’s an interesting discussion and i’ not sure how if what i say will add something but here goes.
You have to think bigger than vending machines. they are not the only access points to soda. if it’s a returnable bottle…people have to be able to get it at the supermarket, at the restaurant, off of street vendors, stadiums. so the your sterilzation process has to be portable enough and fast enough to service these communities. So what you’re trying to do here is change the paradigm of use. so people don’t mind exchanging bottles at any venue…or getting refills. We do it at mcDonalds maybe we can do it at the stadium. but then where do you put the costs of un-regulated dispensed drink. I mean you cna have free refills at McDonalds but if you do it at a 50000 person stadium then who pays for that? As a stadium rep how do you know how much should be bought? You might have to expand the question in order to focus properly.