GOULI, thanks for the exceptionally informative, illuminating, and interesting post. I've taken a full 240V shock accidentally (not in water), and I can tell you, it very quickly gets your full attention!
I was repairing a power tool, got a little "switched off" during repeated "power on" testing, and managed to insert a finger into a live active terminal, incorrectly thinking I'd turned the power off! No harm done, just gave me a good little recharge.
One thing about those small chargers that I don't like is their propensity to "light up" because of their relatively poor construction and poor quality insulation. Remember, you're reliant on possibly one or perhaps two, overworked, underpaid and lowly-skilled Chinese factory workers to ensure your house doesn't burn to the ground!
As a result, I never leave these things running unattended in an empty house. I've had a simple 3-pin male-female 240V extension lead connector, "arc up" via a straight-out short circuit, and it was pretty impressive to see!
The offending 240V connector assembly was in a workshop, running power to a pedestal drill. The power lead hung down from the wall and could swing in the wind that regularly blew through the often-open shop doors. Years of swinging in the wind created the conditions for the 240V connector short circuit.
I've also been informed that the cheap 240V electric kettles have been known to short circuit and cause fires, when the power switch at the wall is left on, but the kettle is off.