Welll.... there's a tiny particle of truth here.

You're absolutely right that the Coriolis Effect is so small on the level of a sink or toilet that it is indetectable and washed out by things like the shape of the sink and eddy currents, but there have been experiments not that much bigger than your sink that showed it.

At the level of a tornado, it results in a statistical preference for tornadoes to revolve counterclockwise in the Northern Hemisphere and clockwise in the South.

And of course, at the global level we have the certainty of the jet stream.