Well...as the Good Book sez, "it is done unto you as you believe" and perhaps if we believe OP can help heal cavities, it will! It strikes me that the period of swishing, for however long we do it, is an excellent time to visualize and affirm the resolution of any mouth issues.
"How much dental work, expense, pain, etc could we have all avoided if we were OPing from a young age!"
I've had the same thought, many times! Wouldn't it be cool if OP and other natural approaches to dental care, could be part of the school curriculum! It sure would have done me a lot more good than algebra! ;)