Call ducks can vary greatly. I have had a baby come out on its own at day 23, and I have had one that needed to be helped out on day 28. Hatches in the same house, same incubator can vary from hatch to hatch. I don't follow some of the "rules"; rather, I candle often and let the egg tell me what it needs, which also means sometimes I have some eggs from the same hatch getting different treatment than others. Spraying/misting is done to help dry down the eggs, not moisturize them, so one has to know where the air cells stand befoe going crazy with the misting, or risk drying them down too much too fast. You also have to be able to recognize when you put the eggs in how much bloom they have on them...have they been washed at all, unwashed or have they had the bloom washed off? Because if you clean eggs before setting them, or your ducks "help out" by "washing" them for you, some eggs lose their bloom easier than others and you have to be careful.
Right now I am running a dry incubator with misting once a day and the eggs are all looking spot-on for this hatch without "renegades" that need individualized attention, but we'll see if that luck holds out. It might, because these eggs were all fairly clean and only needed to be dipped rather than rinsed.
On that "lockdown", I keep turning until I see the internal pip, *unless* I see the duckling has been pushing for some time (a day or two) and then stops. Then I put them to the hatcher to try and stimulate them with the high humidity. I take each egg acording to what it is doing, so you can see we don't have a real "lockdown" here. Calls often seem to like to quit, and my hatcher cycles the temp up and down within a degree, so this allows the hatching ducklings just a tiny titch of relief on the heat while hatching. All of this is still bearing in mind what the air cells in the eggs are looking like; eggs that start to look like they are drying down too much go to the hatcher where the higher humidity puts that process in check. This is also where having an old redwood hatcher comes in handy, as it is easy to get the humidity back up quickly.
