You could try inserting a clove of garlic at night at bedtime and remove it in the morning. You may notice that you can taste the garlic in your mouth. Or you could try a tea tree suppository. You can buy these in most health food stores. It may not be a bad idea to follow up with a probiotic capsule to re-establish the good bacteria.
I had a partner last year and he never failed to give me a BV, like every single time. I took this as a sign that our body chemistries were incompatible. Once I quit seeing him I never had the problem again.