Clown loaches I've had experience with love love love Wardly brand sinking shrimp pellets. Then again, I don't think there is a fish I've met that doesn't. Try getting yourself a small, shallow cermic dish (like the type they use for reptiles) and placing that on the bottom of your tank. Then put in enough shrimp pellets for the loaches and cories to share. Fish that are well fed are less likely to attack tankmates and nip at fins. Although I know clown loaches can get somewhat aggressive, I've never personally have ever witnessed it. I've also never personally have witnessed any fish ever have truck with cories. Even my rainbow shark, a relative of clown loaches, and plecos seem to tolerate the cories even if they chase around all the other fish.
Clown loaches also love snails. Most LFS have little mud snails crawling around their tanks. Where I used to work we would give them away for free. But even if they're not free, it would be worth it to do you get a little 5.5 gallon tank, maybe do some guppies in it, then start seeding your larger 55 gallon with snails from your colony. They will also be appriated by your clown loaches as a source of food.
~~Colesea