if its ick, FW dips wont helps as those buggers burrow below fish mucous preventing from getting affected from the osmolatic shock. however, monitor ur clown, if u see them restless and slimy, very likely its brook aka clownfish disease. it can kill a fish within 8hrs.
bloody scary infection to me. so take note.
just in case for brook, can use formalin which is very effective provided that if u can get a hold on it. if not, use nitrofuran family antibiotics.
all the best.