Bacterial vaginitis is definitely not sexually transmitted. I get it all the time too. I use to get it 4 to 6 six times a year, but this year I'm only at two times currently

. The only drug I have used for it is metro gel. My doctor always prescribes my enough so that if it reoccurs, I have enough for another five days. The bad part is that this stuff is not on the shelf yet. BV is just as common as a yeast infection. It can even cause pain during sexual intercourse if you don't treat it quickly. I've never heard of the ironing your underwear part, but a few things have brought my reoccurences down.
1. Make sure to wipe from front to back. It is said that ecoli from your rectum can transfer the bacteria that grows into BV.
2. Wear light colored underwear. Dark colors give bacteria the chance to grow rapidly.
3. Keep your moisture down. I wear alldays pantyliners to absorb it. Don't use sprays, they have bad effects.
Hope this helps.