Oiling problem. HELP!!!

Uh,,,,,,,,,,,,,,,,actually they DO


EDIT. "Hell if I know," says Rob. Maybe, they DON'T

http://engineerexplains.com/answr/CoriolisEffect1.html

http://www.ems.psu.edu/~fraser/Bad/BadCoriolis.html

https://en.wikipedia.org/wiki/Coriolis_effect#Draining_in_bathtubs_and_toilets