I used to use plastic shoeboxes with holes drilled in the lids to incubate my eggs in ever since I started doing this stuff. But last year I ran out of boxes with drilled lids and had to use my stash of new, undrilled, ones for a bunch of clutches of eggs. Well, it was a learning experience for me, because I thought some airflow would be best for the eggs. I figured I may have problems with those eggs set up in those sealed containers.
What I discovered, instead, was that the undrilled lids helped greatly in retaining the moisture inside those boxes, whereas I sometimes had trouble with some containers with drilled lids drying out if they were at the top of the rack and close to the edges of the rows where ambient temps were higher and air flow around the boxes greater. I didn't have to do a thing with the undrilled boxes the entire incubation period. Matter of fact, with most of them, they were not opened at all from the time they were set up until I noticed little corn snakelets crawling around inside them.
Even a YEAR later, the vermiculite in those undrilled boxes was still damp to the touch. So heck, that is the way I am doing ALL of them this year. And I am pretty confident I will not have to touch any of them the entire (average) 68 days of incubation.