The basic washing process

Wash your litter box with hot water and mild dish soap, scrubbing the sides and bottom with a brush or sponge to remove stuck litter dust and urine residue. Rinse thoroughly until no soap remains, then dry it completely before refilling with fresh litter. Most cat owners do a full wash once a week, though boxes used by multiple cats or in humid climates may need washing twice weekly.

The timing matters: wash the box when it is empty or nearly empty, not when your cat is using it. Many people wash their box on the same day they change the litter completely—usually a weekend day—so the routine becomes automatic.

Key Takeaways

  • Hot water and dish soap remove urine buildup that baking soda and scooping alone cannot reach, which keeps odor from returning quickly.
  • Scrub the corners and seams where urine pools, not just the flat surfaces, because that is where bacteria and smell concentrate.
  • Rinse the box multiple times to remove all soap residue, which can irritate your cat's paws or make them avoid the box.
  • Let the box dry completely before adding fresh litter, or wet litter will clump when ready and smell worse.
  • Plastic boxes absorb odor over time and may need replacement every one to two years even with regular washing.

What you need to gather

You will need hot water, mild dish soap (the kind you use for dishes), and a brush or sponge you keep separate from your kitchen sponges. A soft-bristled brush works better than a stiff one because it scrubs without scratching the plastic, which can trap bacteria in the scratches. Some people use an old toothbrush for corners.

Wear gloves if you prefer—litter box water contains bacteria and urine, so hand protection is reasonable. Have a dry towel or cloth ready to wipe the box down after rinsing, which speeds up drying time.

Scrubbing the sides and bottom

Fill the box with a few inches of hot water and add a squirt of dish soap. Use your brush to scrub the entire interior, paying special attention to the corners where urine pools and hardens. Urine does not rinse away with water alone—it bonds to plastic, so you must physically scrub it. Spend extra time on the seams where the walls meet the bottom, because that is where the smell usually hides.

Scrub the outside bottom too if your cat has tracked litter or urine there. Do not forget the rim where your cat steps in and out; dried litter and dust collect there and fall back into the fresh litter you add later.

Rinsing thoroughly

Drain the soapy water and rinse the box under running water, turning it to reach all surfaces. Rinse at least twice—once to remove the bulk of the soap, and again to catch the soap you missed. Soap residue left in the box can irritate your cat's paws or make them reluctant to use the box, so this step is not optional.

If you do not have running water where your litter box sits, fill the box with clean water, swish it around, and dump it. Repeat this rinse cycle two or three times. You will know you are done when the water drains clear and you cannot smell soap anymore.

Drying the box

Wipe the interior with a clean, dry towel or cloth to remove standing water. Let the box air-dry for at least 15 to 30 minutes before adding fresh litter. If you add litter to a wet box, the litter will clump when ready, smell worse, and become harder to scoop.

In humid climates or during rainy seasons, drying takes longer. Some people leave the box in sunlight for a few minutes if possible, because sunlight naturally kills odor-causing bacteria. If you are in a hurry, you can add litter once the box is mostly dry rather than bone-dry, but the fresher litter will still clump faster than it should.

When to replace instead of wash

Plastic litter boxes absorb odor over time, and washing only removes surface smell. If your box smells bad even right after washing and refilling, the plastic itself has absorbed urine deep into its material. At that point, washing will not help—you need a new box.

Most plastic boxes last one to two years with weekly washing before odor becomes permanent. Metal or ceramic boxes last longer. If you have a box that is more than two years old and smells persistently, replacing it is more effective than continuing to wash it.

Frequently Asked Questions

Can I use bleach to clean a litter box?

Bleach kills bacteria and odor, but the smell is strong and can irritate your cat's respiratory system or make them avoid the box. Stick with hot water and mild dish soap, which are effective and safe. If you want extra disinfection, white vinegar mixed with water works and smells less harsh.

How often should I wash the litter box?

Once a week is standard for a single cat. If you have two or more cats, wash twice weekly. Boxes in humid environments or homes where odor builds up quickly may also need twice-weekly washing. Scoop daily regardless of how often you wash.

What if my cat refuses to use the box after I wash it?

The most common cause is soap residue left behind. Rinse the box extra thoroughly and let it dry completely before adding litter. If the problem continues, your cat may dislike the smell of the soap itself—try unscented dish soap or switch to vinegar and water instead.

Can I put the litter box in the dishwasher?

Most plastic litter boxes can go in the dishwasher on a low heat setting, which saves time and uses hot water effectively. Check the box for a dishwasher-safe label first. Remove any stuck litter by hand before loading, and do not wash it with dishes or food-contact items.

Should I wash the box if I use a litter box liner?

Liners reduce how often you need to wash, but you should still wash the box monthly or when you change liners. Urine can leak around the edges of the liner and pool on the plastic underneath, so the box itself still needs cleaning even if the liner looks clean.