I use colored indicator silica beads for desiccant purposes and when the indicator shows they're "wet"/green, I spread them evenly on a baking sheet with foil and bake them at the recommended temp, stirring occasionally, until they turn back orange.
We bake it on low temperature for like two hours. We did it just once, so we cannot assess whether it's still efficient with the baking energy included.
But the winter is coming now, so the extra heat generated when regenerating won't go to waste.