disclaimer do this at your own risk. i’ve never gotten electrocuted, but i don’t assume any responsibility if that happens to you, or if you cause any damage to whatever your plugging in or your building’s wiring! make sure whatever you’re plugging in can handle the higher voltage (220-240 V). British plugs are ginorm because they have fuses in them, so beware because now your connection has well, no safety (which i suppose is true for anything foreign you plug in). but yeah, i’ve done this countless times.
if you have a two-pronged European plug and find yourself in the UK or another country that uses Type G outlets, you don’t need an adapter! just stick a key or something into the ground (the sole vertical opening) to open the shutters and plug away!
i got this European phone charger (USB plug) a while back and it’s one of the most handy things ever.
I’ve done that trick several times. I’d suggest using something that isn’t conductive to be on the safe(r) side. I wouldn’t, as shown in the gif, use a key as that is metal and conductive. (Conductive, in this context, means electricity can flow through it easily.) A stiff piece of cardboard can work, tightly rolled sheet of paper, etc.
Yes, good point about using something non-conductive! as i understand it, the ground hole should be safe since there’s no current flowing, but better safe than sorry!