I sincerely have a hard time believing that it will work for just about any cat. It will likely result in a disgusting mess and an unfortunate cat who is forced to hold it in and/or have an accident. My cat went for the first week, consistently meowing in an unhappy manor, and used the Citi Kitty in conjunction with the floor and/or scraping whatever was in the Citi Kitty onto the floor.
I feel that even had it been "successful," there is still almost a guarantee that cats will not always be 100% accurate with it and you'll still wind up cleaning the bathroom a fair amount. I care too much about my cat to torture him any further, so I'm tossing this product out, and wanted to warn others about this terrible product!
UPDATE - the unhappy meows from my cat were VERY SERIOUS, and he had a kidney stone from holding it in all the time! I followed their directions to a T and it was nothing but torture and accidents. He would pee anywhere but the CityKitty, so I had to resort back to the traditional litter box. Did that fix the problem? Not really. He was in such pain, he developed kidney stones from holding it in so much. I researched, and due to this, the cats associate going to the litter box with pain, so even with the litter box back in place, he still would pee outside of the litter box, and he started peeing blood since he had stones in him ripping away at his insides. At the vet, after a day and roughly $700 in tests and x-rays, we determined that he had kidney stones, and they were most likely the kind that will NOT dissolve with medicine / special diets. So we had two options - put him on a special diet and keep giving him narcotics and pain killers, hoping it will dissolve in the next month or two, or remove them via surgery immediately. I opted for the latter to make sure we could take care of it as fast as possible. After the expense of the x-rays and tests, we did the surgery, which was about $1,200. For the next 10 days, I had to give him a narcotic twice a day to ease the pain as much as possible. Then after all of this, we went back to the vet to have the stitches removed. He's going to be on a special diet permanently to make sure this never happens to him again.
Oh yeah, and we sent the stones to a lab for testing. They are the type that would never have dissolved.
So, if you are willing to risk your cat going through complete agony, paying a huge medical bill, and basically putting your poor cat through ***; most likely the worst experience in its life, go for it! Even if it works, get ready to clean your bathroom again and again, and deal with the annoyances all along the way regardless.
NEVER even think about using this product!
Review about: Cat Toilet Kit.