The fish will eat once it is not as stressed. I've had amazing success with fresh water dips. If your 100% sure that you have a proper diagnoses, then go about a fresh water dip. There are many ways in which people do this and I have tried them all with only one producing the results desired. Here are the steps:
1) get a Medium dark Dark bowl, anything other than clear and has never seen soap..EVER!
2) Use tap water. just trust me on this, if you do it correctly its the right call.
3) match the temp of the fresh tap water Exactly to that of the aquarium.
4)If your not firmilar with the liquid product PRIME, you should should be. You will need around 1/4 capful of prime for this first dip. (You can get prime at petsmart)
5)do your best to makesure that you make the area as dark as possible(make sure you can see, but this is just to reduce stress to the fish). Also make sure the lights have been off on the tank for 2 hours( this makes the fish easy to catch).
6) you can use a net to collect the fish out of the tank to place it in the dip that you have prepared, however I prefer a basic plastic partycup. I collect the fish into the cup, and then drain almost 100% of the water hes in then swiftly transfer him into the bowl.
7)Now you Watch
8)The clown will be mellow,then calm, melow, then calm, and this will continue.
9) watch the ick itself, you will see it almost appear to take on a look more of an air bubble. Once you see this it is time to remove the fish and do it as quick and smooth as possible. Collect the fish, This time byusing a net, and then place him back into the aquarium and keep the lights off!
She will breath heavy, and may look worse at first but give her a few hours to regain composure. I would not attempt to feed her untill the following day.
10) this process will need to be repeated one more time two days from that first dip.
Then your perc should be look great.*( adding Prime in small doses to your aquarium where the perc is also helps produce a slim coat which is benifical to the recovery process and continued health of the animal) Let me know what size aquarium so I can help u with how you should dose..
Keep us posted..
B