Reminds me of when a friend ordered some San Pedro cactus over the internet "for religious sacrament." It included a note indicating that they ran out of the exact variety that he ordered, but they thought that he'd be very happy with the one they sent because it was stronger when used for religious purposes. (San Pedro cactus contains mescaline. It's perfectly legal to grow for ornamental purposes.)
Mushroom spores are sold online for "microscopy purposes only".
Over here, huffing nitrous oxide is a thing, but it's sold as pressure gas for whipped cream dispensers and the like.