I think you have it covered right now. If you Oxine it a few days ahead of when they are going into it, you should get any stray virus or something that came in on the wind. The thing to remember, they are going to be exposed because it's out there. The trick is to make sure the exposure is done in small amounts so their bodies can handle it and build resistance. You will always second guess yourself now, lol, I know I do. It's just the way it is. As time goes on, you will become more comfortable with it all but your eyes will always be searching for something that isn't quite normal. Whatever that is, lol! I'm not even sure I know anymore. To me, my birds are happy, as healthy as they can be, lay eggs daily and beg me for bread whenever they are ranging. Seems pretty normal to me...but under it all, they have a potential to have an outbreak or be taken by another illness because of what's inside them. Maybe it's weird, but I kinda think we are the lucky ones. We know that nothing is to be taken for granted, our birds seem a little off, we're on it and treat immediately. We've learned to wait and see isn't always the best option for our birds.