Whether deep-frying, browning ground beef, or cooking bacon, we often end up with leftover cooking oil. The tendency may be to pour it down the kitchen sink but that can clog and damage the plumbing, and if it’s poured outside on the ground, it can cause problems for wildlife. You can save your cooking oil to reuse later, but if it’s gone bad or you don’t want it, there some easy, safe ways to get rid of it.