no fish "cleans" your tank. It frustrates me so much when I see someone go in the pet store and ask the uninformed staff "what fish cleans my tank??? Its gross and green, and its gettting out of control!" ah, no. No fish is going to"clean" your tank. Yes, they will nibble at the algae and eat some leftovers off the gravel, but YOU have to clean your tank! Don't put responsibilities on your fish. :/
On to your question:
Khuli loaches do eat extra food off the bottom but they should have sinking pellets as well so they can have a constant food source. They don't really clean.