Most people really have little or no idea how a CD player or a microwave works either. :-) That doesn't stop them from having confidence in those devices, because they're familiar with them and they know that they DO work from past experience. People who are familiar with moving Chi also know that it works, whether or not they know exactly how it does. There are some wonderful texts from Asia which do explain how, for anyone who is genuinely interested.

Yes, acupuncture helps to restore proper flow of Chi and to discharge blocked-up Chi from various parts of the body...parts that could be described as sort of "junction boxes". Too little Chi in an organ or muscle causes weakness. Too much Chi causes burnout or other stress symptoms. It's really a lot like electricity.

Benji, you asked if a bear shits in the woods. I think you should go into the deep woods and see if you can find an actual bear, maybe a grizzly, and ask him or her about this face-to-face for the definitive answer. :-)