I do have a smelly passenger story but I wasn't originally going to tell it as it's bus-related, but it's perhaps relevant because an official line was taken on the person concerned.
In London, on a 73 bus to Victoria Station, I was sat rear seat downstairs: we got to the Marble Arch stop in Park Lane and there seemed to be a hiatus, bearing in mind that at this point there are about half a dozen other routes bound for Victoria, and some of them were beginning to pass us. The 'problem' was a tramp straight out of Central Casting, he appeared to be about 70 but he was probably a good decade younger than me. By this time, and with both doors still open, the most appalling smell was emanating from the front of the bus where this bloke was standing, adjacent to the driver's cab. It became apparent that the driver was refusing to carry him and the tramp wasn't having any of it. In a truculent Scottish accent (see, I told you he was from Central Casting) he announced that if anyone touched him he wouldn't be responsible for his actions. As the thought of touching him wasn't uppermost in anyone's mind I think he was safe! The bus driver, a middle-aged man who remained calm and non-confrontational throughout, was by this time calling for police and, five minutes later, pedal-cycling across four lanes of traffic from Hyde Park came, if not Dixon of Dock Green, his modern equivalent, the oldest police constable I've seen in many a year. Again the tramp started on no-one touching him, to which the constable drolly replied they'd both be safe then, but the driver had said the bus wouldn't continue with him on it, so, please be a good fellow and get off. After about two minutes in which the tramp sized the copper up he mumbled something and stumbled off.
This is not quite the end of the story, because when the bus finally got going we had only gone two stops, to the Park Lane Hilton, when the i-bus announcement came on 'this bus terminates here':we had been turned short. Got off, transferred to the first Victoria-bound bus which came along, and who was standing by the driver's cab?!.....
That happened on the last journey I made on a London bus, having done thousands in my time, and was the only time a passenger had been evicted for olfactory reasons.