I've tried a drop of Dr. B's peppermint, too, but found that I had to follow it with a nice sugary piece of dried pineapple to get the taste out of my mouth. That pretty much wiped out any benefit I might have received from it.
OTOH, in her book "The Complete Tightwad Gazette," Amy Dacyczyn consults a dentist who explains that as long as you're brushing all tooth surfaces for two minutes and rinsing with H2O, you don't need toothpaste. My trips are short and I don't bother with toothpaste, although if I were on a long trip, I'd ask my dentist if that would be sufficient to maintain dental health.