thanks for the added ideas and safety concerns. It has got me just why anyone would sniff the stuff for recreational pursuits !
For draining, I have one of those jiggler hoses, only used it on water so far but gees they work and flow well too. I just cannot suck a fuel hose as I have some severe reactions to the smell of the stuff - let alone the taste !
Before school one morning, a mate, once authorised by his sister to siphon juice from her car to his RM125 tank swallowed

. he did not feel well, and by receess was drinking all available milk, and by lunch you could still see him breathe out petrol fumes . NO JOKE
I used to be a petroleum distribution engineer and had the concoction in my system for sure. If I am driving along, windows shut, I can detect an off loading fuel tanker 500m away just from the tank breather pipes venting blowing my way