It makes a difference
I tried other deodorisers without much success but this one it's good. I have 2 cats with very stinky poo and I can get away without changing the litter for a week without unpleasant odours.
The way I use is adding a tiny bit when I put the fresh litter and then every 3 or 4 days when I have to top up the tray I add a bit more.