a little school of pictus cats are great, tough as nails, max out at 5-6 and really active. the problem with clown loaches is the eventualsize but they do grow pretty slow and always worth a pretty penny when bigger. Clowns have little barbs on the side of there mouth and with them being so boistrous tended to wind my bigger cichlids up, where the pictus got ignored apart from my jag which didnt like the whiskers. good luck with whatever you choose
Honestly i have a pictus and a raphael and they seem to do an ok job. I had a small group of cory's before when the cichlids were smaller and they seemed to do better. I personally love the clown loach they are so energetic and have tons of personality! but as far as cleanliness goes i say id give it to my dwarf crayfish hands down. Little guy wouldn't leave any stone unturned looking for food and would hold his own against against the fish trying to take a nip out of him. They only thing you have to worry about is when they molt but mine seemed pretty smart and would hide in his cave until his skin toughened up. He did love to eat his fair shair of tiger barbs though lol.
I had a red tail shark and a blue botia. They were the only fish I've ever owned that exclusively ate fish poop. I love MTS I wish my cichlids wouldn't eat them. Corydoras can occasionally get stuck in the throat of cichlids with their little spines doesn't happen often -but when it does it's a terrible thing