Peter, what did you smoke? 
lots of plastic bottles to pee into
Not a problem in a Mirage. Relief tube!
How exactly does the relief tube work?
Obviously it can’t just go straight out, in a pressurised plane.
I’ve seen them but not what is underneath.
Presumably you also need to rinse it out otherwise it will smell 
There is a lever which you press which opens the tube to ambient pressure. You are indeed supposed to wash it and the underside of the aircraft after use.
That is why I use traveljohns instead.
On the later Mirage there is a ball sealing the bottom of the drain connected to relief tube. The ball floats up when immersed in liquid opening up the tube to ambient pressure and the outside which ends up streaking along the underside of the belly.
AFAIK nobody ever uses it due to the corrosive properties of urine. :-)
E
