Blumsden,
When direct seeding in the field, it is important we get the chestnut about 1 inch below ground surface. Yes we water that location enough to prevent the ground from sucking all of the moisture out of the chestnut. We select a location that gets full sun and does not have standing water on the nut / roots during period heavy rainfall.
Container growing. MattPatt hit the nail on the head about how many die in the wild. We only see the ones that survive. If you want to container grow, good drainage matters, soil that don't compact matters, aeration matters.
How often do I water? Depends on outside temperatures, sun and wind. This requires some observations by you. I would start out watering either on the odds days or the even number days of the month. That is a starting point - adjust it from there. Your growing media may do well with that schedule or it may not. You just have to dial it in.
Think of watering as feast and famine. We don't want either period / situation lasting very long. Water them good and then let them get dry for one day and then water them good and then let them get dry for one day. We probably don't do that in a heat wave.
When temperatures hit the 90s and hotter, I water mine every single day - this is an" adjust it from there" example.
What people overlook with containers? If your containers are outside and they have chestnuts in them, they better be protected. The lord gave those critters an excellent nose so they don't starve to death. They will find them and destroyed many, all or most. That makes me angry. It happened to me once - then I build some protective cages.
Soil collected from the ground and put in containers most times will become much to hard for aeration and drainage. This is a common mistake that increases the losses.
If I am thinking right, you are buying a garden type growing soil that drains good. That is a choice that can produce excellent results if you adjust accordingly on the watering schedule.
I want to answer your questions because I want you to be happy with your results. Sometimes if I read too many posts in a hurry, I don't answer the questions as well as I should.
This response addresses each type of growing situation. I hope I have answered better this time.