If, upon your return, the ice cubes look like they melted and refroze, it'll alert you that a power failure occurred and some of your frozen goods may be spoiled. Don't discard marshmallows when they dry out and harden. Just put them in a plastic bag with a fresh slice of bread. It'll soften them. Squirt lemon juice on windowsills and the bottom of doors.
Ants hate it.
Add a few grains of rice to your salt shaker to absorb moisture and keep the salt from clumping together in humid weather. Set it well away from the fruit. If you drop a raw egg on the floor, sprinkle salt on it and it will wipe up easily. To quickly dry fingernail polish, dip your nails in ice water. The polish will harden much faster.