My parents cat is an inside cat most of the day and goes out for a bit at night. They keep a tray for her in the laundry, although if she needs to go during the day she'll just stand by the back door until someone let's her out. She barely uses the litter but occasionally there are times where someone doesn't let her out in the morning and she'll use it. They use a clumping litter (I forget the brand it comes in a plastic carton, like a big milk one). When I lived at home she was still quite young so would use the tray quite often and I've never noticed the laundry smelling.