The food grade sanitizer would work great, too. My friend that raises waterfowl professionally uses a very mild bleach solution. You could also use Oxine or Vanodine. I have a friend that swears by each of those, too! LOL!
My waterfowl raising friend is the one that recommended the cooling process to me. I just know that I went from dismal hatch rates to 80% (and more) when I started cooling. And though the hatching guidelines that Diana posted are excellent, I would change around the days that are cooled. It is better to cool the embryos later in the incubation, rather than earlier. That is in my humble experience and per the advice I have been given. I am not an expert at anything.
As far as humidity - my friend also recommends the dry hatch method, rather than higher humidity. He says to watch your air cells closely, and if they are not shrinking, your humidity is too high. And getting the eggs too wet at the end can drown the little ones as they try to hatch. I did that to a couple of batches. You do need to raise the humidity a bit at the end. My friend recommends a small sandwich size container of water in the large incubators. If you don't open the incubator during hatching, the humidity will raise with moisture being released from the eggs.
And, as far as the cooling off period not being proven - I don't know what to say. You could try it. It worked for me. Geese get off their nests and stay off longer than chickens do. I have watched them. They seem to almost forget they are brooding - then finally go back. If you try it and it works - great!! If not, then don't do it again. Experimenting with what works best is the best way to learn.
There is also controversy on turning the eggs, especially as frequently as a turner does. This is about chickens AND waterfowl. What that says to me is that you have to learn what is best for you!! One time one of my turners broke and I didn't notice it at first, but then it had been a while so I left it. Just curious. I had the same hatch rate as the ones that were being turned.
Horizontal is best for waterfowl eggs, as in the article.
DeAnna
PS> Read Diana's info whenever she shares it and learn from it. She is like a walking encyclopedia of information about poultry. She is a doll!