Can i use a homeopathic insert (vh essentials) to help keep good bacteria in vagina while taking antibiotic to treat bv?

You can but...: Their BV insert is promoted as an alternative to antibiotics for bv. It's safe to take with antibiotics but it is unlikely to affect good flora (but if used without antibiotics might resolve your infection without harming good flora- though no guarantees!). Their prebiotic suppository (which isn't homeopathic) supports healthy flora but will likely work better combined with inserting probioitcs.

Yes.: Some doctors and homeopaths recommend a douche with yougart that is an active culture. Yougart has lactobacillis which is a good bacteria and normal to be in the vagina. Bacterial vaginosis is a bacterial infection. Yeast are also part of the normal vaginal flora. The antibiotics kill the "good bacteria" and then the yeast grow unchecked, and cause the irritation or "yeast infection".