From the deeps of memory come a couple of other examples of "really dumb" weapons triumphing over high tech...
In WWII, NZ soldiers had some success in flushing German troops out of trenches and foxholes in the desert by throwing stones.
The theory, which apparently worked, was that if, at night or in poor light, something landed next to you with a thud, you got out of your hole quicksmart rather than wait to see if it was a grenade.
Why not simply throw a grenade I hear you ask? Probably because, true to British tradition, they weren't in as plentiful supply as they could have been....
During the Soviet incursion into Finland in the same conflict, the Finns managed to take out Russian tanks, using tree branches. The method of operation was to hide behind a tree until the said armour was up close and personal, and then dash out and jam a suitably-sized log into the tracks.
Nip back behind your tree while the tank comes to a grinding halt, and then pop out and shoot the first unfortunate crew member who gets out to see what's wrong.
The Russkies faced a grim choice; stay in your tank and freeze to death, or get out and get shot. The account I read did not mention any Finnish respect for hastily improvised white flags.