What did the yeast culture say? I am experiencing the same onion Body Odor , I definitely think it's a fungal overgrowth in the gut, my problem started when I started to take Antibiotics , it then gave me jock itch and the onion scent came once my body got hot, enen minutes after a shower the scent came back, I managed to get rid of it twice but the scent came back after Antibiotic usage, here is what cured it, prescription of Terbinafine 1 tab per day for 3 weeks and it was gone, including the jock itch...also the second time I used an over the counter product called "Holistic Candida cleanse" in combination with Acidophilus and my scent came back to normal.Hope this helps