At first sight, Louise Elliot is not the most profane name that could be given to a child. Parents with the surname Elliot could generally feel comfortable that naming their baby daughter Louise will leave her safe from ridicule from her peers. It's just ordinary, isn't it?
In the hands of a master japester such as Stephen Foster, however, every single syllable is ripe for scatological sarcasm. And thus your child shall forever be tarred with the monicker Poo Wees Smelly Butt.
I've no idea what Stephen Foster is doing now, but if there's any justice in the world he should be editing books of babies' names to warn parents about just this sort of thing.