Your plot points reminds me of Pink Flamingos. This probably isn't the film your looking for but if you were to squint and mute the dialect as you watched, It'd be pretty damn close. All I can say is any film where turds are eaten of the sidewalk and also given as gifts. Well that just speaks for its self. Gross. Still no wooden baby to my knowledge.
Not Pink Flamingos, but it does sound like something Waters would do...happy birthday to him btw.