The earth’s rotation or your position according to equator have nothing to do with the way water drains from your sink or toilet. This is a common misconception that always make me shudder when I hear it I want to clear up. I guess “nothing” is an over statement, but the effect is so many orders of magnitude smaller than all the other factors, for instance, the angle at which the water enters, the shape it the container, etc. People chalk this is up to the Coriolis Effect, which does have influence on a much larger scale such as hurricanes and storms, but not in your suburban bathroom. You can read more about it here. So go try it and realize how small you, and your toilet, are on this planet.