Cat and litter box help

Hi! So several months ago, I took in 2 sibling cats from a home that was just horrible. It was filthy and stinky (and so were they). They were scared and tormented by other cats and dogs. When I showed up, there were several different litters of kittens and dogs. I originally came for one of them, but seeing the conditions, I took 2. It didn’t take long for them to warm up.

Anyways, they have never used a litter box, up until I got them. One uses them now (we have 3, one on each floor), but the other doesn’t. He refuses to use the litter box, at least 80% of the time. He’s peed on clothes, my baby’s diaper bag, and even my serving tray that I sat on the ground one day to use for drawing with my kids. Whatever is on the floor, he will use it. Their litter is clean and done every day, and I thought he’d grow out of it too, but he hasn’t. There doesn’t seem to be any other issues when talking with a vet. I’m just not sure what I could do? Maybe switch the litter?

Definitely try a different type of litter. Also, if the boxes are covered, I’d take the lids off because most cats prefer uncovered litter boxes.

Yeah it’s uncovered XL so they have plenty of space. I will try different litter!

Every time the new cats use the litter box, compliment them and offer a treat. They will understand that it is something cool to do.

If everything else fails, ask/borrow another cat who is familiar and good with the litter box usage. In two days they’ll all learn from it.

Is he neutered? If he’s over 6 months or around that age, they start spraying. If it’s extra stinky, then he’s not peeing, he’s spraying. It’s territorial.