Hydrogen Peroxide is an effective mouthwash. It's also very cheap!
It's all that I use and was recommended by a dentist. It also gives you instructions on the bottle on how how to use it as a mouthwash. I don't dilute it though, but it's recommended to. I love it because it doesn't just seem to cover up your breath odor, it kills the bacteria. So gargle and swish away :) Brushing your tongue and flossing should be part of your regimen, too.
For toothpaste, Toms of Maine has xylitol, which shouldn't pose too many issues. It's what I use and I love it. It's fluoride-free if that concerns you.
*It's interesting what you say about sugar, I tend to agree*