Have you researched all toilets in these countries thoroughly??
The answer is that the water doesn't spin in opposite directions or in the same direction...
The water spins in the direction the design od toilet directs it to, and please do not mention the Coriollis effect, it is tiny compared to the design and shape of water jets and toilet bowl...
Next daft question!....it is Xmas after all I guess!!
John.
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A little knowledge is a dangerous thing - Googling is far worse!