Don't sweat it if they get in pool. But they will need to be watched. In the wild it is common to see little ones swimming behind Mama duck. And if you watch for awhile, you will see JAWS is a real thing to ducklings, in the form of a bass.
You are Okay until that come at you like that hissing!
So many moons ago I worked at an apartment complex with swans and water canals between the buildings.
Typically we co mingled unless there were babies. Then we wouldn't work the nest areas for a few weeks.
You have a very valid point regarding the need for protective gear. There are different types of DE.
But please don't fool yourself into believing it is worse for the environment that pesticides, let alone the everyday products used in kitchen and bath everyday.
I have been to many facilities...
I have a TX mutt. Next door neighbor passed, so I tossed her in my truck. Coast to coast, week after week, she is 1 of the most loyal dogs I have had.
Now her job is to protect our first little flock. Hopefully that bit of dog brain won't override her training. So far so good. I have heard...