How odd! Given the context, I would have expected the first word to be a woman's name. In certain clubs in certain parts of the world, "ladies who entertain" do a trick where they insert a pingpong ball in an intimate part of their anatomy and then fire/shoot it across the room using only the muscles of that part of their anatomy. I was unaware that men did the same sort of thing with a slightly different part of their anatomy.
So basically, the word "whatoosie" here has been used to replace probably a rather rude word for the anus.