I have 7 Clown Loaches ranging in size from 3-6" roughly and whatever my cichlids don't eat, they do. All that's left on the bottom of my tank is poop. I also have about 6 fancy pleco's in this tank too.
Even with bottom dwellers you will still have to maintain a regular cleaning schedule. I keep light stocks in all of my tanks but I still do a weekly water change. I'm not saying that you have to do a weekly change, just don't ease up on your maintenance once you get bottom feeders. You'll be introducing more fish and therefore more waste in the water and the substrate. Most of the things that water changes help to cure can't be seen by the naked eye. Water changes really keep your water parameters in check. That being said, Clown Loaches and Cory Cats make great bottom feeders. Just make sure that your fish don't try to make a snack of the Cory Cats. Their spines will lodge in the predator's mouth, killing both the Cory and the fish trying to eat it.Yeah my moms tank has absolutely nothing on the bottom of the tank, not even poop. I just dont want to have to change it as often if I can get something that wil keep it cleaner