Don't send the leftover cooking oil down the drain, it can block the pipes in the sink. Then you will likely have a bigger mess later and need to call a plumber when the pipes eventually clog. Instead, let the oil cool in the pan then pour in an old container you don't mind throwing away, like a can or a butter tub. Put the oil into the container, then you can throw it out with the trash. Depending on the oil you use, oil that has turned into a solid once cooled can be placed in the trash with a spoon. Find more tips on using and reusing your frying oil before you toss it here.