I just have one son (adult and living far from home) but, I know of the scent. I used to blast everything in his room with Febreze - it didn't help. He was out here for the holidays and I just realized the "scent" is gone. Maybe they outgrow it at some point.
They do. Our son smelled like a fermented onion during that time period. As a matter of fact, I think he was called 'Onion'.