Premier Date: October 10, 2003
The full premise is that too many bricks in the barrel accidentally lift the bricklayer, who hits the barrel on his way up and hits pulley at the top. When the bricks hit the ground, the bottom of the barrel breaks and the bricks fall out, causing the bricklayer to fall back to the ground, again hitting the barrel on his way down. Finally the bricklayer lets go of the rope and the barrel falls on top of his head.
The MythBusters were able to replicate several elements of this myth, but only by deliberately weakening the barrel and dropping it on a sharp edge were they able to get the barrel to drop its bricks. The source of this myth was discovered to be a joke book from 1918.
Although it is possible to electrocute yourself by urinating on a third rail, you would have to stand unrealistically close to the rail to do it. In most instances, a urine stream would break into droplets before making contact with the rail.
(This concept was tested with an electric fence in episode 14 and that version of the myth was confirmed. Distance is the key.)
Most eel-skin wallets are not made from electric eels, but rather from a fish called a hagfish which does not produce an electric charge. Data written to a set of test cards was not affected in any way.