It’s all about the microflora
As both a woman and a vagina lover, I have some thoughts on this subject.
I think it is telling that so many people make analogies to wine, vinegar, and damp beach towels (on the good side) and cheese, rot, old fish, etc. (on the bad side). What do all of these things have in common? They are all fermented. That is, all of these things have smells created by bacteria and yeasts. Like the smell of sweat, the detectable odor of a vagina is created by the mini ecosystem of invisible creatures that live there.
Because nasty things like infections and diseases are caused by bacteria and yeasts, the very idea of that stuff has kind of a bad rap. However, there are many healthy and beneficial bacteria and yeasts that live in our bodies (and our vaginas). It seems very likely to me that the smells produced by those bacteria and yeasts–which vary from person to person–would play a strong role in attracting a mate.
Vaginal bacteria has a strong connection to overall bacteria in your body (especially the digestive tract) and many schools of medicine believe that a healthy digestive system is the foundation of immunity and good health. So I think it would make a lot of sense from an evolutionary fitness standpoint for the most attractive women to be the ones with the best-smelling vaginal bacteria (and hence the strongest immune systems, best genes, etc). It also explains one reason why women have pubic hair: to grow more of that attractive bacteria and diffuse its smell. (I think at least one guy on this thread said that a woman he was with shaved her pubes and had a disappointing lack of scent.)
I’m not too familiar with the problems surrounding copulin products. The issue is that synthetic copulins aren’t convincing enough? I wonder how much better they would work if the pheromone was delivered through an authentic vaginal bacteria smell.
If I had to make the perfect copulin mix, I don’t think I would try to assemble the smell by adding an acid note, a salty note, a honey note, an oceanic note, etc. I think I would culture the bacteria and yeast from some healthy ovulating vaginas, then try to isolate the smell of that stuff. OR MAYBE! I would even try putting some real live bacteria and yeasts into a product. Our noses are very sensitive, it might need to be the real deal and not just a similar smell. If you did create a product that was literally alive with that bacteria/yeast, I would experiment with making it an oil or gel, and maybe add some sugars into the mix to keep the bacteria/yeast alive and active.
OK that’s my crazy idea for the day!