I've read that kefir has better staying power than yogurt, so I wanted to suggest ladies utilize kefir rather than yogurt for bv treatment. And that some strains of probiotics produce hydrogen peroxide, which strains are probably preferred.
The box of Bv cream from the store came with reusable applicator tubes that can be used for applying yogurt or kefir, etc. rather than a syringe if you don't find one.
If the Bv returns during your period you could try treating rectally those days. For example, mince fresh garlic, let stand 10 minutes to activate, add to olive oil and apply as retention enema.
Thank you for the wonderful website!