Kitty Litter Curbside Trash Never Flush Down the Toilet Harmful parasites live in your cat’s waste and can end up in the pipes and septic system. Even if it’s labeled “flushable,” don’t flush it down the drain. Throw It Into the Garbage The best way to dispose of kitty litter is to scoop waste into a bag, tie the bag tightly, and then throw the whole thing into the trash. Ways to Reduce Switch to Biodegradable Litter Silica and clay litters don’t decompose and can also be harmful for your feline. Try using a newspaper or wood pellet litter that is biodegradable. Ways to Reuse Use Clean Litter as Mulch If you have extra unused litter that is natural and biodegradable, such as wood pellets, you can use it as mulch or garden fertilizer.