Being a mere old European, I've never had the pleasure of consuming one of these, but here's a recipe I found.
1 1/4 cups orange juice
1 cup water
3 tablespoons egg white or egg substitute
1 teaspoon vanilla extract
1/4 cup sugar
1 1/2 cups ice

Combine all of the ingredients except ice in a blender and blend on high speed for 15-30 seconds or until the sugar is dissolved. Add the ice and blend for another 10 to 15 seconds or so, until ice is mostly crushed yet still a bit coarse. (http://www.topsecretrecipes.com)
Makes 2 16-ounce drinks.

Giok