Here in Germany there are a number of beer brands that come in a swing top bottle:
(picture taken from Wikipedia; copyright by Michiel1972, license GNU/GFDL)
I often heard the claim that you should leave those bottles open before returning them, because otherwise it would harm the beer producer, create additional work and cost, be bad for the environment and raise the beer costs.
Most of the time when you ask people claiming such things, they will tell you that in order to clean and reuse these bottles, the lids have to be open. If the lids are not open, they have to be opened manually and the company has to hire additional workers for that in their factory.
I find this very hard to believe, especially considering the massive amounts of bottles that are returned for refilling every day. The factories surely are able to open those bottles automatically if this is necessary for cleaning and refilling them.
Is there any truth to the claim that you should leave the bottles open?