The "Caccolube" was a simple but effective device to disable an enemy vehicle. It was a condom filled with abrasive powders and crushed walnuts, and was dropped into an engine crankcase. "After the engine heats up," the OSS manual explained, "the hot oil will deteriorate the rubber sac and free the compound into the lubricating system.
"When circulated through this system, the compound fuses and welds the moving metal parts of the machinery. Slipped into a truck, the Caccolube takes effect after the truck has been driven from 30 to 50 miles. It reacts so thoroughly on pistons, cylinder walls and bearing journals that the vehicle is not only thrown out of service but the engine is destroyed beyond repair."
This lethal "lube job" replaced the original effort using sugar, when it was discovered that sugar actually promoted better engine performance in the vehicles of that era.
Source: Jack Anderson, "Rare arsenal used by spies," Santa Cruz Sentinel, Mar 9, 1987.

In certain types of warfare, for example, insurgency as practiced in Southeast Asia, enemy infiltrators and insurgents resort to extensive tunnel networks to hide from the established forces. The tunnel system in any one area may be elaborate and may traverse several levels and numerous branches with the arrangement being such that the insurgent forces are disposed in the system in such a position that a high explosive detonated at the tunnel entrance will have little effect on those hiding in the tunnels because of their labyrinthine construction whereby the direct force of an explosion is screened from the occupants. Because of the danger of booby traps or ambush it is not practical for attacking forces to enter the tunnels with the result that heretofore there has simply been no way to kill or dislodge insurgents hiding in the tunnels and the broad object of the present invention is to provide means for exploring tunnel networks by a self-propelled device which can be safely controlled from a remote position outside of the tunnel network.

More particularly, it is an object of the invention to provide a tunnel exploring device which may be maneuvered from a remote position deep into the tunnel network and there be detonated so that there is a much higher kill probability of the enemy forces with greater safety to the attackers than has been possible by any means employed heretofore.