If it is possible to get a larger waterer, or more than one, that would be one of the first things I would do. At the same time, I would make or buy a platform for the waterers.
I am also struggling with the splashees, and for my 15, I have found that a previously unused two-piece broiler pan (bottom is solid, top is slotted), covered with a section of old towel, makes a good base for the waterers. The towel provides traction, but most of the water drips down into the pan so there is not a swamp. It in turn, keeps the bedding in the area more dry. All I have to do is lift out the waterers (which need rinsing or washing and refilling), lift out the platform, plop the dirty wet terry cloth into the "diaper pail," pour out the spilled water, poop and crumbles, rinse the pan off, put a clean dry piece of terry cloth on the pans, replace the pans, replace the waterers, and we are good to go for hours. If it sounds like a long list, the whole activity takes perhaps three minutes.
That pointed out, I have read that it is only okay to feed moistened food if it is removed frequently because it will mold very quickly, which can be deadly to ducks. And they still need water with their food, no matter what. They also need to be able to dip their bills into water to clear out their nostrils.
People who grow orchids have something they use to keep orchids more humid while keeping their roots dry - it can look like honeycomb and sits under the pot - something like that under the waterers might work well. I spend quite a bit of time cleaning up after my darlings
, but this time of their lives is so short. And each week, there is a new consideration to adjust to. I am using towels for bedding now, but will be switching to pine shavings before too terribly long.
Hang in there, this stage is temporary, what you learn now will help during their next lifestage.
