Ketones/acetone in your breath doesn't smell like shit, it smells slightly sweet. If your breath smells like shit at this point, you need to be rehydrating with water and enough sodium/potassium so that you don't have a dry mouth.Dry mouth and subpar oral hygiene is what causes shit breath.etones/acetone in your breath doesn't smell like shit, it smells slightly sweet. If your breath smells like shit at this point, you need to be rehydrating with water and enough sodium/potassium so that you don't have a dry mouth.