Unless you are good friends with a land owner good luck getting access to "rid the area of pests". Land owners do not let just anyone on their land, much less somebody who has no experience hog hunting. There are a multitude of resources out there but I recommend going on a guided hunt and learning the ropes. A case of beer or two is an insult, try 300-1000$ per night per person.
I recommend hunting hogs at night, they are more active once the sun sets and the temps plummet. In order to hunt at night you'll need some specialized gear but if hogs are what you want then its a must. Missouri is not packed with Feral Hogs like places in the south (Texas, Georgia, Florida) so unless you start baiting hogs a week or two before you show up you probably will not see them, unless you are very lucky. Hunting over baited areas, or wide open fields using thermal optics to detect and identify them is one of the better ways to do it.
Check the State hunting regulations, here in FL no lic. is required to hunt hogs on private land, they are considered domestic livestock and you can take them by any means available, pistol, rifle, shotgun, bow, AC-130 Gunship, or Predator UAV, day night and season is 24/7/365. Other states treat them like a holy talisman and regulate hunting of hogs with an iron hand.