(link)

... Boiling Wand
"This portable water heater—the better to make [[tea]] or bouillon in the privacy of your hotel room—was a must for every Soviet traveler," Idov says. "Russians abroad had a reputation for shorting out whole city blocks by plugging these babies into 110-volt sockets. The infinitely more terrifying homemade version consisted of an electrical cord, two matchsticks and two razor blades."

...

I don't know what the matchsticks are for but this is great.

Apparently they still make these, and they are still liable to blow fuses if plugged in while not immersed in liquid.