i've been on a raw food diet for 5 months now, my breath has improved ALOT but it's still there, i've heard from a few people that it takes about 6-7 months for the smell to be completly gone.
If you're wondering how i'm able to live on that diet, well this is my last resort, it's a matter of survival - life or death. When you reach the bottom of the barrel and you equate cooked food with death, it's quite easy to stick to the diet lol. But i suspect this approach only works for people who are at the end of the rope, i.e, after at least 10+ years of BB.