Years ago my drink was once spiked with GHB at a big Vegas-themed costume party. The perp was a nondescript stranger who helpfully held my drink as I took my turn at the roulette wheel. I very quickly became horrifically ill. Luckily I was there with my sister who got me help. It may have served the would-be rapist right if I had indeed fallen into his hands. As it went, it took a while for the EMTs to believe that I had not brought my condition upon myself. I was costumed in visible garters and kaleidoscopic drag-queen shoes, and my sister pleaded for help wearing a teensy, vintage chain-mail halter and pink leather skirt. "We don't usually dress like this! She didn't take anything!" I vaguely recall her repeating. I was very out of it, and I think my sister ended up more traumatized than me; she still likes to say that the "emblem" of that evening was the image of my false eyelashes, afloat in the ambulance vomit basin.
So as not to end on that note, I'll add that if I had this product-of-the-future, I would be eager to try it out. I would probably make eyes at some creep and then leave him alone with my drink, just to have the pleasure of doing a little science experiment.