A long time ago, someone told me that American soldiers in Vietnam who hated thier commanding officer would sometimes put a hole in a ping pong ball, fill it with bleach (or was it kerosene?), caulk the hole, then put the ball into the gas tank of the the officer’s jeep. The ping pong ball would slowly disintigrate, the bleach (or whatever) would hit the engine and the whole jeep would explode. Is this a true story? Thanks if you know.
Maybe it’s true but it seems like a lot of trouble to go to when they could just shoot him during a firefight.
I doubt bleach would make a jeep motor explode, much less blow up in such a way to kill the occupant. Tequila on the other hand might just do the trick.
There would be a reaction if gasoline is sufficiently acidic (I’m not sure of the ph level of gasoline, nothing came up on google). It’s certainly possible that the explosion could blow up the gas tank, though it might not be enough to kill the CO.
A ping-pong ball would hold about two tablespoons of liquid. I doubt that two tablespoons of anything mixed with the gasoline in the tank would cause any sort of explosion, especially in a Jeep’s low compression engine.
A better option would be to use a heavy rubber band on the spoon (that is the hadle-thingee) of the grenade. Drop the assembly into the (very wide, by the way) gas filler cap of the jeep.
At some point the rubber band melts and the grenade spoon flies off, the grenade explodes right under the driver’s seat.
Don’t even ask why I know this.
I am guessing that not every soldier had the “benefit” of having his CO in front of him during a firefight 
Especially those that were far away from any fighting.
Somebody putting something into a gas tank with the intent of having that substance EXPLODE!?! That’s insane, that’s crazy, that’s like putting :::gasp::: GASOLINE in a gas tank!
A couple tablespoons of bleach would do nothing. The CO would probably thank the nitwit now-sub-private for cleaning the carbon off the piston heads. I personally would be more concerned with the plastic from the melted ping pong ball clogging the fuel filter.
One reason I doubt this is that given the length of time it would take to dissolve the ball, the uncertainty of when it would happen, the fact that the jeep would be used by or carry others, etc. means that who knows whom (?) might be killed by this.
“Get in private and show me that tunnel you found yesterday.”
“In that jeep, sir?”
“Yes, in this jeep.”
“Sir, can I draw a map instead?”
“Get in the jeep private.”
“Has the jeep been sitting in the sun a lot lately, sir?”
etc.
Anecdotal evidence that this is an UL: I have always heard (a long time ago, someone told me) that if you pry off the cap to the gas tank, put a ping pong ball in there and replace the cap, it was a great way to cause problems for someone: Supposedly the ping pong ball floats down onto the fuel line feed, seals the hole, and the engine stalls and shuts off b/c there’s no more fuel. When the driver pulls over, the ball floats away again, the engine starts fine, the ball gets sucked over the hole again later, same result, etc. The problems come when the owner tries to get the problem fixed - the fuel pan being the last thing mechanics replace to solve the problem.
Thank you everyone for your replies. I guess it’s a myth.
This is an old bit of revenge advice from the Anarchist’s Cookbook. There are variations. 1) just drop any old ping pong ball in the tank 2) fill the ping pong ball with bleach/ammonia/Drano etc and tape closed. There might be others. Will it mess up your gas tank? Sure, but so will a dirty rag or a bag of sugar. Did soldiers use it in Vietnam to kill their COs? No.
“I am guessing that not every soldier had the ‘benefit’ of having his CO in front of him during a firefight Especially those that were far away from any fighting.”
But why would a soldier not in combat really WANT to kill his CO? It’s my understanding that, to the degree “fragging” isn’t a myth, it wasn’t done for shits and giggles or just because the CO was a martinet, but specifically because one or more soldiers thought the CO was giving orders that endangered the unit’s (or the individual soldier’s) survival.