As of mid-September 2026, here in Riverside, my kitchen disposal still gets the ritual it has had for most of my thirty years in this ranch house: a handful of ice cubes to sharpen the blades, the breakfast eggshells to scour the chamber, and the morning coffee grounds to leave it smelling fresh. It feels like maintenance, so it sticks.
Then I read the City of Riverside’s own page on what should not go down the drain, and two of my three cleaning tricks are on it by name, right next to hair and dental floss.
What Riverside Public Works says
The city lists food waste, coffee grounds, eggshells, hair and dental floss together under one heading and says plainly: “These materials can clog pipes and are difficult to remove from the sewer system.” Its instruction is just as short: food waste and other debris go in the trash, not down the drain. That is not a chore tip about a fresh-smelling sink. It’s the city telling you what ends up stuck in the line behind the wall.
Why the ice does nothing
The blade story falls apart on its own. Angi’s repair cost guide explains what is actually spinning down there: garbage disposals “don’t actually have blades like you’d find in blenders or food processors. Instead, they use dull hammers to grind—not chop—the food waste in your sink.” One disposal maker’s own FAQ answers the blade question with a flat no: no blades, no knives.
So there is no edge for ice to sharpen. And the eggshells and coffee grounds aren’t scouring anything on the way through. By the city’s list, they are simply more of the material that can clog pipes further down…