New questions are welcome - yes, it's as you say, the cut end heals / callouses over in a dry area. You can leave it for a few days, a week, or a month. Succulent plants are like that.

Cacti are even better. I had a Neoporteria multicolor that lost its roots. I knew it would be months before it was rooting season. The spines on that one are like straw, so I carried it around for several months (not all the time of course) I showed it when giving tours at a botanical garden to illustrate that lack of roots was not lethal. In the late spring, I put it on the right soil and it rooted.

The point is, after the plant callouses, it may not root right away. Depending on the species, sometimes they do, but sometimes they wait for the right clues from the sun or the temperatures.

I have had aloe hang around rootless on the shelf from October to March and then it got its yellow nubs and took of. I have had cactus and opuntias hang around in the shade till someone knocked them onto the ground and I got another plant. Sometimes when I cut a pad, I dust it with cinnamon to prevent rot or fungus. Some cactus and opuntias need to callus for longer than a couple of days. We don't water them and only mist them till they have roots.