I have never cleaned everything after cocci. I figure it lives in my soil, and I can't clean the dirt. The new chicks usually catch it and I am prepared now! But once they catch it and recover they are immune, so you don't have to worry about it anymore.
I was told that even when they have recovered from cocci they can still have some occasional bloody stools for a week or so as their intestines heal up. I continue the Corid for 7 days, then give them powdered milk in their food, ACV in their water, and set out some plain yogurt once a day for a couple days. If they start acting sickly again, you can give the Corid treatment over. Corid isn't the same as an antibiotic, and the avian research PhD guys at our university told me that you can give it for extended periods of time without major side effects. It does block the absorbtion of one vitamin, I forget which, so if you give it for several weeks then I would follow up with no iron added poly-vi-sol baby vitamins.
The first time my birds got cocci I used Sulmet because
TSC didn't have Corid. I lost a lot of my chickens. The Sulmet didn't work. They got better, but then then it seemed to come back, over and over until they eventually got weak and died. Apparently Sulmet is also a lot harder on their systems. Now that I use Corid, I haven't lost a single chick! (I found that the only store in my area that carries Corid is Southern States...) I have also found that if you aren't giving enough Corid then it won't work. I give 10 cc per gallon and I have given a little more than that before if it doesn't seem like it's working fast enough. The avian research guy I called also told me that it takes a very high dose of Corid to harm a chick, so it's alright to give a little more than the recommended dose at first to really knock the cocci out.
If you have a university near you with an agriculture school I highly recommend calling them and asking questions in situations like this! I learned so much from the guys in our universities department, and they love to talk about birds, haha.