I pun ada cat yang sebelum ni suka sangat kencing outside of his litterbox from time to time, but Alhamdulillah now dah behave
First of all, of course mesti rule out all health issues first (urinary tract infection etc). Tapi kalau dah betul confirm that it's not a health issue, but instead a behavioral issue, then maybe you can try what i did.
Kucing ni once dia dah kencing kat one place, no matter u cuci dengan air & sabun macam mana banyak pun, the smell will never be completely gone (hidung kucing memang power). So they will go back & kencing at their fav spots again..and again and again...
I solved my problem by buying an enzymatic cleaner (in spray bottle). Enzymatic cleaner ada enzymes yang get rid of the cat pee & poo odour completely, so I cuci semua tempat yg dia pee, and also spray banyak2 kat tempat2 where he is likely to pee, especially area just outside of his litterbox - and i solved my problem overnight!
Pastu, u kena spray tempat2 tu on a regular basis pasal kalau the cleaner dah lose it's effect, your cat might start to pee at those places again. So must always keep this spray handy la.
Best part is, murah je. I guna spray Fido, which is like 8.90 kat Tesco.