Arm & Hammer Ultra Last Cat Litter Review: Unscented Performance Tested

Quick Verdict

The Arm & Hammer Ultra Last unscented clumping cat litter is a solid mid-range option that delivers where it counts: firm clumps, genuine odor neutralisation, and nearly dust-free pours. The 18 lb bag is heavy and the granules run on the finer side, but after six weeks with two cats I kept coming back to it. It earns a 4.2 out of 5 — easy to recommend for multi-cat homes and anyone tired of fragrance-heavy litters.

What Is the Arm & Hammer Ultra Last Cat Litter?

Arm & Hammer built this litter around their old reliable — baking soda — and wrapped it in a clumping clay formula marketed as a low-tracking, virtually dust-free option for multi-cat households. The "Ultra Last" branding signals long-lasting odor control even if you miss a daily scoop, which, let's be honest, happens to everyone.

This is the unscented variant, so you're getting zero added fragrance. That matters more than it sounds. Our older cat, a persnickety tabby named Margot, has turned her nose up at scented litters her entire life. Unscented clumping cat litter options are rarer than they should be, and the Arm & Hammer version steps into that gap without cutting corners on the core clay performance.

Key Features

• Baking soda granules embedded in every scoop actively neutralise ammonia odors
• True unscented formula — no added fragrance to trigger sensitive cats or humans
• Tight-clumping clay forms solid waste bundles that don't crumble when scooped
• 99% dust free on pour, protecting your lungs and keeping the floor cleaner
• Low-tracking particle size reduces litter scattered outside the box
• 18 lb bag designed for multi-cat households and bulk buyers
• Online-exclusive sizing — not always easy to find in physical stores

Hands-On Review

I set up the Arm & Hammer Ultra Last in our primary litter box on a Thursday evening, replacing a well-worn competitor brand that had started leaving a faint ammonia whiff by midday. The pour was smooth — no surprise dust clouds, just a soft settling sound. I noticed the granules felt slightly finer than what I was used to, which gave me a moment of hesitation about tracking.

By the first morning, the clumps had formed cleanly. I scooped and found the waste bundles held their shape even when I tapped the scoop. That's the test that matters most to me: overnight clumps in a multi-cat house need to survive a busy household, not just a single cat. By day three, the litter box room no longer smelled like a litter box — a subtle but meaningful difference from the previous brand. The baking soda genuinely works, not through masking perfume but through actual chemical neutralisation.

Tracking was minimal on our hardwood floors. I found maybe three or four granules scattered near the box each morning, compared to the dozen-plus I'd grown accustomed to with cheaper litters. On the low-pile carpet runner we use as a secondary mat, the granules didn't embed — they sat on top and were easy to sweep up.

Two weeks in, I accidentally let the box go a full 36 hours without scooping during a busy weekend. The odor was present but not overwhelming — noticeably less aggressive than I'd expect from most clumping litters left that long. That's when I understood the "Ultra Last" name. You get a grace period that cheaper litters simply don't offer.

Who Should Buy It?

• Multi-cat households that need odor control that scales with more daily use
• Cat owners with fragrance-sensitive cats who reject scented litter outright
• People in small apartments where the litter box room connects directly to living space
• Buyers who sometimes miss a daily scoop and need a litter that forgives the delay
• Anyone upgrading from budget clay litter and wanting noticeably better odor performance

Skip this if you live alone with a single cat and scoop religiously every single day — you won't notice much difference from cheaper options. Also skip it if you prefer a strongly scented litter that leaves your home smelling like artificial spring meadows. This litter is designed to smell like nothing, and that's the point.

Alternatives Worth Considering

If you want comparable clumping and odor performance but with a different texture profile, the Purina Tidy Cat Clumping line offers firmer granules that some cats prefer for paw feel. It is scented by default but available in an unscented variant.

For households prioritising sustainability, the Okapi Natural Corn Cat Litter provides a biodegradable clumping option with minimal dust, though odor control falls short of baking soda-based formulas in my testing.

The Dr. Elsey's Precious Cat Ultra is a step up in granule size and dust control, making it ideal for cats with respiratory sensitivities, though it carries a higher price per pound.

FAQ

Final Verdict

The Arm & Hammer Ultra Last unscented clumping cat litter does exactly what it promises without overselling it. Baking soda odor control is real, the clumps hold, and dust stays low enough that I'm not dusting the floor around the box every week. The 18 lb bag is a workout, and the finer granule size means your scoop will need more frequent scraping, but those are manageable trade-offs for the performance you get in return. For multi-cat homes, small apartments, or anyone whose cat simply refuses scented litter, this earns a clear recommendation from me.