Dave
In case this is not a joke, you are referring to the Coriolus Force. Think about taking off in an airplane from a point on the equator, and heading due North. Looking at a globe you could run your finger in a straight line and point to where you would land at 40 deg North, right? Wrong! the Earth would rotate under you and your path would appear to cuve to the right (clockwise). It works the opposite way in the Southern Hemisphere, because the equator is the widest part in relation to the Earth's axis. This plays true for large weather systems - Southern Hem low pressure systems spin clockwise - counter in the North, but toilets are not really subject to this, it's just their design. Flush away and don't worry.