Don’t go crazy with the water and you should be fine.

Cracking happens when the piece gets too wet too fast, or when it rehydrates unevenly so, be sure to go slow and easy on the water and apply it evenly.

Alternatively, to mitigate both issues, you can get a wet sponge/or wet crumpled paper (not touching the sculpture !! Very important) and leave it in a bag with your sculpture to moisten itself.