100% dry hatch or partial dry hatch?

[Tex452]

Humidity is different across the country, ours in the Bryan Texas area is usually high this time of year, unless we get a cold front, then it is lower, I watched a lot of videos on dry hatching and decided to give it a try, I will know this weekend how it will turn out.
These are barnyard chickens I got from one of my sons, I want to get it right before I start hatching wyandottes.

Several started pipping this morning, how long should it take after they start pipping to hatching out?