I let mine swim in warm water, and only for maybe a minute at a time on various occasions throughout the day before towel drying, and physically holding them next to the light until they're mostly dry to the touch.
I think I babied my first batch, they were scared of the water!
The next time around I let them swim much more often.
They have their own pool in their pen now, with no problems getting in or out (like some ducks I've bought as adults without pool access). Just make sure you have a cinder block (I use one of the solid halfblock kinds) or bricks to use as a step to get out.