Split the vanilla bean pod and scrape out the seeds. In a bowl, combine pod, seeds and sugar and mix well. Cover the bowl and let it sit at room temperature for 24 hours, to infuse the sugar with the flavor of the vanilla.
Peel and cut avocado into 6 (1/2-inch) cubes. Lightly salt the avocado. Put the cornuts in a heavy-duty plastic bag. Using a rolling pin, crush the cornuts. (Don't crush them too fine.) Transfer the cornuts to a plate.
Slide a avocado cube onto the end of each skewer. Roll the avocado in the cornuts to coat.
Heat the cotton candy machine. Put the vanilla sugar in the extractor. When the cotton candy begins to form, dip the avocado skewers, one by one, and twirl to cover.