First thing the "theory" that the bait makes them thirsty and they will leave to find water is 100% false. So is the moth balls and dryer sheets. Moth balls are made from a byproduct during the production of gasoline. Naphthalene, the active ingredient in the moth balls will do more harm to you and your family than it ever will to deter rodents.
Get some good old fashion wooden snap traps and use a variety of "baits". Use small pieces in the trigger. Try chocolate, hard candy, bread, peanut butter or cheese. Put at least 6 of the traps out in the floor board with one of the baits on each trap. Mice are naturally very curious and will "check out" some new smell as soon as you leave and shut the door. Be sure to check the traps every day.
Good luck