WOW! That really is a sucky start to the new year. I've never had clown loaches before but would recommend small dosages of medication with Copper Sulfate in it. We've used it to cure many things on scaleless, and sensitive fish. I've seen some medication on Dr.FosterandSmiths that is safer for scaleless and sensitive fish, but still uses copper sulfate.
So think of that, It's always helped for us. BUT!!! Do your research about it first, like I said, I've never had clown loaches.