I have seen similar methods of defatting a duck in a number of cookbooks. This one works very well. Without first defatting a Long Island Duck, it is very easy to set the oven on fire (ask me how I know) because of the amazing amounts of fat that pours out.
From “Keeping Company” by Moira Hodgson –
Bring a large pot of salted water to a boil. Add a duck, bring to a boil and simmer for 5 to 7 minutes. Remove and drain. Salt the duck. Using a hand-held hairdryer, dry the outside of the ducks for 8 minutes, wiping away the drops of fat that appear on the surface.
After this, you can cook the duck normally. Hodgson’s recipe uses a ginger, garlic and thyme mixture which is pretty good.