Here is a good professional trade article on processing, marketing and storing ducks:
http://www.dpi.nsw.gov.au/agriculture/livestock/poultry/species/duck-raising/processing-marketing
It also addresses waxing:
Waxing carcases to remove the remaining feathers is recommended where many ducks are to be processed, because remaining feathers are removed quickly and a better carcase appearance results. Waxing carcases to remove remaining feathers is common overseas, and more Australian processors are now using this method. The carcase is covered with molten wax and placed in cold water to harden the wax; when the wax is peeled off the carcase, any feathers come with it. The wax can be used again by remelting it and pouring it through a screen to separate the wax from the feathers. Commercial blended wax can be obtained for this purpose.
http://www.dpi.nsw.gov.au/agriculture/livestock/poultry/species/duck-raising/processing-marketing
It also addresses waxing:
Waxing carcases to remove the remaining feathers is recommended where many ducks are to be processed, because remaining feathers are removed quickly and a better carcase appearance results. Waxing carcases to remove remaining feathers is common overseas, and more Australian processors are now using this method. The carcase is covered with molten wax and placed in cold water to harden the wax; when the wax is peeled off the carcase, any feathers come with it. The wax can be used again by remelting it and pouring it through a screen to separate the wax from the feathers. Commercial blended wax can be obtained for this purpose.