They all say that about the chill, but reality is the glands will start producing earlier when exposed to water. You just have to do it correctly so they don't chill or drown. This means some form of vessel that allows them to get out of the water and never leave them alone. The key is to give them warm water and to watch them sitting next to them. They will eventually slow down playing and that is when you have to take them out. You must dry them off and put them back into the brooder. That way they don't chill and they even start good grooming behavior early on. So mine are in the water at day 3. Now they are as water crazed as my 6 month old golden retriever. You can also get a small space heater for the bathroom and get it nice and warm in there. Do not have it blow directly at them, just get the room nice and hot. That way you can put a towel into the tub after draining it and just leave them there until dry. I do that once they are 1.5 weeks old. Its amazing how fast they get the water out of their hairy downs. They are fast learners.
Katharina