There are 3 methods to defrost a frozen duck without the possibility of food poisoning; you may use the oven, using cold water, and even in the microwave. Never defrost at room temperature. Soak the duck with its original package or in a waterproof bag to thaw in cold water, then change the water after 30 minutes. In around 2 hours, a 4-6 lbs. duck can be defrosted. An entire frozen duck may take 1 to 2 days or longer in the fridge. The duck parts would be thawed roughly one day.