I did a master cleanse for 33 days if I still remember right and by then I became weak, emaciated, and started to get smelly all over again. I don't regret it, but I wish I would have stopped 10-15 days earlier. Doing it for 40 days isn't going to help. Master cleanses are great, but too much of a good thing can turn into something unhealthy.

Pantothenic acid is very nice for improving digestion and helping the liver, which then helps the breath. Even if you aren't sure what exactly is causing the bad breath, I would say try it for a few weeks. It might help a great deal.

Lovey