I would use this activity to show students the challenges of removing spilled oil from the environment. I will also give them a pretend budget to buy materials from me for them to use to clean up the oil so they can understand it can be costly as well.
Earth Day Experiment ~ Can You Undo Water Pollution? In this experiment the kids learned just how hard it is to undo water pollution. a bucket of clean water, some household trash, vegetable oil (to stand for toxic oil spills), tongs, and a strainer.