I can't speak to them all. I have been happy with the rug doctor product "urinate eliminator". it comes in a red spray bottle. you can get it wherever they rent rug dr. carpet cleaning machines.
you are going to need enzyme cleaner to get out the urine. a cats sense of smell is something like 300x better than a humans. you may think it is fine but to a kitty it is not.
i have been in your situation and know the sense of frustration. try removing or covering up with plastic the things or places he has been urinating on outside the litter box. Get a new littler box.make sure each cat has his own littler box. One of cats for whatever reason started going on the...