Not entirely true. They will not "go" where they sleep if the place they sleep is small. Example: I have a mini Daschund. When I got her I kenneled her during the day and every day I would come home and have to clean out the kennel, and her. You see, even the smallest dog kennel if to big for a 8 week old mini-daschund. She actually fit in the palm of my hand when I brought her home.
If you kennel, buy a kennel that will fit your pooch when it is full grown, then be smart... block off most of it and let the pup grow into it. That way it will get used to having a small area to be in, and will not "go" in their sleeping area.
When I get my lab, hopefully after duck season, I plan to crate her and attempt to train her myself. This forum will thankfully provide a lot of good info.