They are in fact real, and have been used to some success. However, I do not reccomend their installation and we cannot support systems that have them installed. While a large buildup of ducks has caused problems for many users in the past, we've made huge improvements to the duckception handler and the upcoming 15.0 actually has similar features to these poultry cards.
A little known fact is that small amounts of ducks are good. You'll be fine without any at all, but one or two can actually improve coolant circulation. (Especially if you use coffee, ducks really like coffee.) While the results are delicious, the cards i've seen nuke all the ducks and therefore speed their return, as the ducks are attracted by a warm place to nest.
But now, with 15.0, DKDC can detect when there are more than 2-8 ducks in a system (depending on size/power) and will broil them. It'll even marinade them for you so you can have it for dinner, in fact using a DKDC system as a duck-preparing-machine will not void warranty as of 15.0!