A request for an inside view. The difficult part was finding a tub that fit the dimensions of the cabinet. Lots of larger litter boxes are 17 inch wide. I found rubbermaid tubs at Office Depot that had almost the perfect dimensions. One of the cats is a high pee-er so the walls had to be tall. The 18 gallon tub is even taller than than the smaller one I went with. I cut a hole in the front, not easy to do, I used heavy duty scissors and then went over the new edges with a piece of sandpaper, it didn't feel particularly sharp but I wanted to make sure. I have the shelf set so they have ample head room, I wanted it to feel very spacious. Obviously you don't want your dishes in the same cabinet because of litter dust so all my cleaning supplies are stored in the rest of the cabinet.
Technically I haven't had them use the cabinet yet with the door shut and the new hole. I painted the opening white last night and let it dry overnight. I'll get back with you if it doesn't work. All our cats have used covered litterboxes so I didn't feel like it was very different if anything they get extra head room and extra privacy, but I could be wrong. Also they've been using this cabinet with the door open and without the door for weeks and we've had no problems. I do clean the litter box at least twice a day, this is a must with so many cats. I'll let you know how it goes today with the new hole.
I also had a question about the inside of the cabinet. It is laminate inside but it's totally glued down solid. It's easy to wipe up. If it gets wet too often like under a sink with a leak it might start to peel up. Under my sink for precautionary reasons I put down a puppy pad so if it does drip it's on the pad. This is overkill but I spent most of last fall resolving a bug issue and water is the biggest issue with bugs. I've never had to change the pad, I don't think it leaks at all, very little if anything. In the cabinet, as you can tell, I don't have anything under the tub. I thought about putting a puppy pad there but so far I haven't had any issues.