What is the dreaded black dust inside so many pins from Europe.?
Is this black dust in all machines that come from Europe.? Is it in home use pins as well or just container pins.?

Its in any machine that has had a lot of play....

... its the sooting from arcing across contacts. For the arcing to happen, an electron must leave one side and deposit on the other... this is not however a perfect transaction as the electron ( sometimes more than one) will not deposit completely and sometimes goes astray so to speak. Also known as the Edison Effect, it predicts that often when an electron leaves it will not deposit but will break down ( carbonise), this is also why contacts become pitted.. the pitting causes the Edison Effect to become more frequent.. and so a vicious cycle begins... more sooting and less electrical contact to work from and to.
Edison Effect will occur anywhere that electrons are passed through a medium from one contact to another.

Same effect happens in flouro tubes ( blacking on ends) and also neon tubes... the electrodes gradually over time break down and cause tube failure. In a flouro... approx 12months.. in a neon tube.. approx 10 years or more.

Or it could be diesel inside the machine......???LOL!!!????