The term Bill Cosby used in a comedy routine/story, meaning penis. In this scenario, he'd just stepped out of the shower and began peeing in the toilet standing up. His two toddler-age daughters open up the door, walk in, and start to yell and point at his "wally-wally" and ask if they will get one. He yells at them and they leave him wondering how he's going to go about explaining sex to his daughters (because he forgot to several weeks before).

When you eat dirt for the first time and leave your family to build a shack in the woods

it's a slang word for a male's ding dong. Comedian Bill Cosby used it on a comedy sketch on his "For Adults Only" comedy album.