Whacky weaponry worthy of James Bond's technical adviser, "Q", was considered but abandoned by the Home Office as a way of dealing with violent protests during the past 25 years.
Behind the grim lines of police officers confronting protesters have been psychics, wild-animal trainers and the inventor of a rucksack water cannon with a kick so powerful that wearers of the device in trials were knocked flat.
Records of the Home Office's scientific development branch show that chief constables were also offered sniffer foxes, machines capable of hurling multiple tennis balls or beanbags, and an adult water pistol which squirted an immobilising toffee substance. This caused particular excitement at the section's laboratories in Hertfordshire until a volunteer target was nearly suffocated by the goo.
"The substance was very hard to remove and was a health risk to the target through blocking up airways," said a disappointed report. The foxes also proved a letdown because they refused to be tamed, and bit their handlers before chewing through their wire-mesh enclosure and escaping en masse.
The litany of failed brainwaves is detailed in the Home Office's policing magazine The Sharp End, which has collected the experiences of the 14 specialist staff at the experimental branch. Their tests did sanction some familiar police weapons, including baton rounds, Taser stun guns and CS gas sprays, but the list of failures is a lot longer.
Every example started with a bright idea, such as foxes' exceptional sense of smell, or the value of something between a Super-Soaker water pistol and a truck-mounted water cannon. The backpack hoses went to the final stage of development in two forms - a continuous spray and one which fired "lumps" of water - but both knocked their wearers off their feet.
The tennis ball mortar was "wildly inaccurate" and the use of extra-sensory powers never really got beyond first base. The branch was sent an inventor's pack of cards with minus and plus signs which, according to their ratio when dealt, were supposed to show if explosives were nearby.
It might not seem so whacky in the context of toffee guns and tennis balls, "but the idea didn't get very far", said Tim Sheldon, the head of the branch's explosives and drugs detection team.