Yeah. I swear some of my ducks have had competitions to see who could waste the most water. It is amazing how much of a mess they can make 😆!
You could try pea gravel right under the waters. I found it helps with digging. I haven't wanted to use too much of it, cause it is not as nice on their...
There are several different ways people go. Some people do sand. Others like leaves or straw or hay.
I find that if I provide a water with holes for them to put their head in but not swim they dont make a mess around it. No more giant holes. They don't need to have a bath all the time. Maybe...