More and more of my flock just keep getting sick and I'm trying different antibiotics but the noticeably sick don't seem to get any better. If I decide to cull the flock, before I get new chickens what should I do to make sure that the new chickens don't get sick from the leftover residue of the old chickens? Should I go around with a spray bottle filled with bleach and water? Any help you could give me would be appreciated. I haven't decided what I'm gonna do yet but I just want to be prepared.