I have heard that eating a vegan diet eliminates a certain ammonia smell to the body and severely reduces B.O. I wonder it nonenal is from a long life of eating animal products. I know this is a lot for someone to try to not eat meat or dairy, and it would take some time for it to help. I think the best essential oils for this out of my knowledge would be rosemary, with a carrier of olive- as well as patchouli, a favorite plant in India for it's properties of masking malodors. Maybe apply directly to skin, or place in a capsule for consumption.