Thanks, BakerAunt, for sharing this article. I can see where it might work for the home cook. Occasionally, I need this trick, so I will be trying it sometime in the future.
This works on a small scale in the microwave, too. I still have a few hot cross buns from last Friday, I spray the top and bottom lightly with water, put them in the microwave for 20 seconds, and they're nice and soft. (Let them cool for a minute or two, though, the raisins can get quite hot.)
I've done it with stale hot dog buns, too. (Those I often wrap in a paper towel.)