I would suggest leaving a supply of dry CGD along with the wet stuff while on holiday may be a reason for offering CGD dry. Reducing wasted, dried out CGD is another. Reducing the amount of cleaning of encrusted bowls of uneaten CGD may be a third reason. As to dehydration of the gecko, I'm not sure this occurs. While I do follow the instructions on how to reconstitute CGD, I do leave it inside the enclosure for 24-48hrs post mixing. At this time, I see a change in consistency of the CGD and would suggest that it does become more concentrated the longer it stays in the enclosure. There have been reports from others that their geckos like their mix thicker, or on the second day, or even a little runny. I guess the point is how do we know what the optimal proportion of CGD:water is allowable when we don't know the concentration the geckos actually prefer?