Have you ever tried a nipple type device with ducks? Everyone says they have to submerge their nostrils, but I've never had a problem with brooder ducks. I imagine if they're out burying their snoots in dirt, they'd need to clean them out, but for just days of shake down, they'd be fine.
I'm pretty sure ducks can get really sick if they can't clean their noses. Mine got crap all over the beaks.
But my forays into nipples was unsussesful so um not an expert.