I found this product to be pretty much useless. It doesn't spray well; it leaks out so your fingers get wet and slip; it takes FOREVER for it to dry (put the box outdoors for at least 2 hours in the sun and breeze and it was still tacky when I brought it in); the first couple of piddles come up quite easily, but by the third piddle in the same spot, you're back to scraping the bottom per usual.
And I made the mistake of buying TWO bottles!
It's a great idea, but as far as I'm concerned, they did not succeed with the product.
Brought this as a test as one of our cats was aging and began to have kidney problems with the resultant "sticky" urine clumps gluing themselves to sides and bottom of litter box. After using this I can only recommend it, the 'non-stick' effect gets better with each use. I spray the litter box with 2 light coats after washing it out and definitely notice a difference. I use it even after Sam has passed and also spray the scooping tool.
I have used this for a few years after finding a sample in the pet store. It works great at keeping the litter box and scoop from caking up with litter. Heard about using cooking spray instead, but that was a mess.
First off, I don't even use clumping litter, so I can't speak to whether it keeps the clumps from sticking, although I'm sure it would help. I thought it would make the box easier to clean and it does- without getting too detailed, it's great at preventing fecal material from sticking. A side benefit that is awesome is the smell. It is supposed to be catnip scented and it has a very light herby-foliage kind of smell that is very pleasant to both me and the cats. It smells real, NOT perfumey. GREAT!