Big Bang Problem

The coriolas effect only really has an impact on large areas due to the nature of how it is caused. Since rotational speed around the earth axis is faster than at higher or lower latitudes, air, water, ect, as they travel away from the equater either due north or south ( or at other angles, but right angles just simplifies the problem), the realitive velocity around the axis remains constant, while the speed of the earth around the axis decreases the further away you go. The realitive velocity difference is what causes the effect. A toilet or bathtube are so small that there is virtually no noticable effect. Generally, even the form of the bowl or tube, without any jets, will have a greater, often orders of magnitude greater, effect than the coriolos effect.

If I remember correctly, the conditions of the tub and the effects on it had to be greatly minimized, and it was slowly drained over the quite some time to generate teh effect. In lab conditions, it is reproducible (barely), but for your typical toilet or bathtub, you will never see the actual effect.