Hi. Some people exclude using toothpaste. Even in The Master Cleanse boards some believe it's a chemical and it defeats the purpose of fasting to clean your body out. I get that. I, on the other hand, use natural toothpaste (no flouride n stuff). Some people don't agree with that either because most natural toothpastes have xylitol. BTW I also use baking soda and food grade hydrogen peroxide. Personally though, the gawd awful breath is an issue. I'm okay with natural toothpaste since I'm not eating it and I rinse my mouth out pretty well. Additionally, It hasn't affected my fasting and I'm on day 8. I think it's up to the individual. That's just my 2 cents.