That's a bit strange because in the 10 years I've lived in the UK, I've never, ever encountered the term "B.O." meaning "body odour."
Then again, if you pronounced Beo like bay-o or be-o (not bee-o), that association would be shifted away a bit.
~I luv London Tipton 'cause she's an idiot like moi~
My pinool:
http://www.behindthename.com/pnl/149249