Science hasn't figured out all the causes of body odor except for maybe TMAU.
What might work for some body odor disorders might not work for others.
A vegan diet won't alleviate the odor over night, it takes time. There is no magic overnight remedy....yet. Be attuned to how your body reacts to different vegetables. Some vegetables may cause an increase in body odor while others might not.
For body odor? Yes, I believe it will. Especially great for a cleanse, and if you don't want to stay at raw vegan, you can go regular vegan which is beneficial too. After that you will feel what is the best balance for yourself, even if you decide to go back to eating animal products occasionally, or more often.
"Fetor hepaticus or foetor hepaticus (see spelling differences), also known as breath of the dead or hepatic foetor, is a condition seen in portal hypertension where portosystemic shunting allows thiols to pass directly into the lungs. It is a late sign in liver failure and is one of the clinical features of hepatic encephalopathy."
If you read Newports post about Hepatic Encephalopathy you will see that it's associated with the liver not being able to process protein.
Which results in excessive ammonia.
Anyone with TMAU should get their Ammonia levels checked.