in theory the dog will learn potty only outside first...and that the bells are his key to get him outside...but making that connection happen isn't as easy as people think...
I think the dog wants to go outside...and just happens to pee out there...so people think the dog wanted out to go pee....I think the dog just wanted out and happened to pee.
most of the time at least... Iam sure that it can be taught like a behavior chain and the dog can understand it, but I don't think thats what most people are really seeing, at least at first.
did that make sence? Lol
either way no harm...you can always take the bells down.