Hi QuilliamShakespeare
Hogs do sometimes decide to spend the day in feed boxes. It happens from time to time here. They usually only stay a day or two and then move on. I usually then continue to use the box as a feed box. But once it is vacated, before you continue to use it as a feeding box, I would be inclined to clean it out with boiling water to get rid of any parasite eggs in any cracks (assuming it is wooden, not plastic). Because if a hog has been sleeping in there, there is more chance that it could have left some parasites or their eggs behind.
But it depends whether the hog has made a nest in there. I had a hog once who built a full blown hibernation nest in a feed box. As it happened he decided not to hibernate but used it for days intermittently and for naps between snacks. If there has been a nest built in your box I would leave it be and use something else for feeding.
