Thanks for the warning, I knew that they can hold high voltage chargings but not that it was that long.
By the way I once got zapped by a faulty TV set. It was on, were watching as usual, wanted to turn it off at the main power switch at the front. When my finger touched the knob, I saw a trail of sparks running from the bottom part of the tube over the plastic frame into my finger. That considerably hurt. Was afraid of these things for months after that incident
(It was propably just the usual static charge, but it was a big enough amount for my finger to tingle for an hour)