We told an annoying ex public schoolboy acqaintance that drinking the stinking, rancid, three year old bong water would get him very high, and that it was a huge treat to be allowed to do so. I’ve never seen anyone puke so hard and long.
Also (and this one wasn’t deliberate)…. I stayed in student halls for a short spell. Right next to the halls was a park where you could always expect a decent crop of magic mushrooms. Me and a few mates picked a few bags full and spent a happy hour condensing them down into a viscous black liquid. We poured it into one of those 500ml Coke contour bottles and left it in the fridge to cool down.
At the time, a Chinese neighbour had managed to squeeze a family of five into his tiny, one-man room. One of his female relatives necked half of our mushy brew thinking it was Coke. We sat in my room listening to hysterical screams and debated whether or not to tell them what was happening, but by that time we were well into a full on trip, and were all too scared to do so.