What's a good way to get the aroma of cat pee out of a concrete floor in an area that's hard to get to?

There are several cleaners with an enzyme that will neutralize the cat piss. I don’t know if this is the best but I used something similar with good results. I like cats but I’m never getting another one.

Edit: Should have read your description… Yes I’d try it.

That stuff recommended by @ARE looks fine, or you can look for something called FOLEX which my local grocery store happens to carry and which is both cheap and absolutely effective. The key is the enzyme component. “Cleaning” is always a nice thing to do, but it won’t eradicate the pheromone. For places where you can’t actually clean very effectively, like a hideyhole under the stairs, this spray stuff is a lifesaver.

I love it that you put the whole episode in terms of Milo “having a pee”. Like having a little treat.
Which I’m sure it was. “Oh look, a new place to Have a Pee! Gail will be pleased.”

I’d think a bottle of Lysol or bleach water or Pine Sol would work just as well. Maybe use a long handled mop to sop up what you can and then spray/swish the mop around in a bucket of bleach or Lysol etc. and swab the deck in the house that Milo built. lol

We’ve used Nature’s Miracle ‘Advanced stain and odor remover’ for years for cats’ and dogs’ accidents (from either end). We use the 1 gallon liquid product.

Lysol, bleach, and Pine Sol too pungent and nasty. None of us want to breathe in those fumes. Plus mopping in the confined space is almost impossible. We can get the vacuum wand in part-way. (“We” being my supple daughter and her boyfriend, who can insinuate themselves into part of the crawl space without needing a chiropractor afterwards.)

Pine Sol and Lysol can be fatal to cats. Nature’s Miracle is you best bet. Get a wand sprayer (used for spraying deck cleaners) from a big box like Home Depot, will not need to rinse or mop it up.

I suggest Nature’s Miracle. We had a dog that would urinate when she was petted and the stuff did work miracles.

Soak it with a mixture of ammonia and water. Once it has sat for a while, apply paper towels or some other absorbent material to soak it up, then let it dry.

The last thing I want is more ammonia fumes. And there’s no “it,” but a spread-out area.

Nature’s Miracle, for the win. I already purchased it; one spray bottle and a refill

My landscaper and friend, who has 3 huge dogs (one named Beowolf and the size of a Shetland pony) , 3 cats, chickens, rabbits and turkeys, is on his way over with his commercial vacuum to the rescue. He laughed when I told him the story and says he keeps gallons of Nature’s Miracle on every floor of his house and barn.

Milo is sleeping happily in a patch of sunlight on top of my piano and looking innocent.

There are no nasty, pungent fumes with ¼ cup bleach in a bucket of water and maybe some dish soap. In fact, it smells wonderful.

We have also used Nature’s Miracle with great success.

Round one of vacuuming and a serious spraying of Nature’s Miracle complete. Apparently Milo found some appealing piles of sawdust in the crawl space. The odor is less severe now but still very noticeable. So we’ll keep at it.

It feels compulsively wonderful to have cleaned that space after 28 years.

One week and three serious sprayings later, the memory lingers on.(Does it ever.) I have several containers of baking soda and coffee grounds in the space to see whether they will act as deodorizers.

Thank goodness I have a flexible guy on tap for the next month who can put on his knee pads and face mask and crawl in and spray.

I am about to purchase another refill of Nature’s Miracle.

One month past the original felony and four serious spraying with Nature’s Miracle, the aroma lingers. Persmart suggested a more advanced product, urine odor specific, also from Nature’s Miracle. Vet talked about some citrusy product that I cannot find.

Any more thoughts? (The felon is snoozing away happily on my piano, not a care in the world.)