Thanks for the feedback.
A certain odor does not necessarily indicate a problem, especially if you have already seen a doctor about it and a problem has been ruled out.
Odor is analogous to sweating, and can depend on time of day, diet, daily activities (e.g., sweating), and can even vary through the menstrual cycle.
The primary focus is on non-pharmacological measures, including those you have tried. However, I suggest that you only use water for hygiene, not soap.
Vagisil products and douches should ideally be avoided.
You mention that you have been doing this for several months. If there has been a recent change in odor, and/or any other new symptoms, it would be prudent to consult a physician.
In this regard, the manufacturer of Prevegyne states that it can help reduce the symptoms of an infection, but not treat it. Therefore, I believe that a medical consultation is necessary in order not to delay management.
I hope I've been helpful, and if you have any further questions, please don't hesitate to ask!
Tom Samaha, pharmacist