Reddit mentions of Resolve Pet Expert Carpet & Upholstery Cleaner - Removes Stains and Odors, 22 oz

My cat hasn't pooped in the litterbox for several years now. Rarely he'll try starting there, but he always ends up running and scattering the poop along his path. Our best guess is that he has (had?) something painful when he poops, which spooks him and makes him run away. Maybe even litter dust? There's no blood and the vets haven't been able to find anything. He seems perfectly healthy otherwise, and he's 17, so we're just resigned to cleaning it up for the rest of his life.

We use this cleaner, which seems effective enough as long as the poop is solid. Use a wet wipe to clean off the worst of it, spray the cleaner, come back with paper towels to press it dry ~15 minutes later. That's probably easier than shampooing every time, at least.

As for potential solutions, there are a couple things that sometimes help for us. We leave a paper shopping bag on the floor for him to play with, and sometimes he'll poop in one of those instead of on the floor. I've read that some cats prefer enclosed litterboxes, but we haven't tried that. Sometimes he'll start on a towel on the floor, so there might be some preference there. Towels are much easier to clean than carpet! I've considered getting some puppy pads to try, but haven't done so yet. The pads are pretty effective for my uncle's dogs, and sometimes his cats use them instead of their litterbox. On the other hand, sometimes the cats pee on the pads and then try to "bury" it, which just crumples the pads up and sometimes makes them leak, so... be alert for that possibility.