Most people like to incubate themselves to help insure proper temperatures and humidity. You tend to have a higher hatch rate if you incubate them yourself. Also, while the female is incubating eggs, she usually won't eat, which takes 2 months that you could have been feeding her and getting her ready for the next season.
Corns aren't like bps and won't incubate their own eggs. They set 'em and forget 'em. So while I suppose you could keep them in the tank in a humid egg box, there's no good reason, too. Especially if the egg laying box is open, you'll constantly have to be remoistening the medium to keep the eggs from drying out.