Finally, on the night before Passover, some families perform a ritual search of the house for any leftover hametz. Usually parents hide 10 or so visible bread crumbs in different places. Then, with their children, they take a wooden spoon, a feather, and a candle or flashlight and search the darkened house. When they find a crumb, they use the feather to brush it onto the spoon. After the search is completed, what's been found is either burned or scattered to the wind.
Spring cleaning comes immediately to mind.
Special dietary rules for a period of time. There are numerous parallels. But more to the SOL point, regardless of faith, all can learn from the ritual search for hametz. We can learn about making a regular and concentrated effort to rid ourselves of the detritus, the debris that hides in the corners of our lives. We can learn that to achieve an important goal, we need to focus.