The advertisement may be largely historic, but the slogan is still frequently used in Dutch as an expression to criticize someone who pretends to give an objective opinion, while actually promoting his own interests. Some recent examples in national media:
- https://www.demorgen.be/opinie/wij-van-wc-eend-adviseren-wc-eend-b54a3e4a/
- https://www.nrc.nl/nieuws/2017/02/11/de-haagse-stemming-pvv-draait-denk-trolt-en-pvda-wc-eendt-a1545611
- http://www.volkskrant.nl/opinie/wc-eend-wetenschap-grijpt-om-zich-heen~a4172288/
- https://www.nrc.nl/nieuws/2017/02/13/pvda-voert-campagne-met-wc-eend-6674123-a1545887
- http://www.parool.nl/opinie/-duizenden-amsterdammers-elke-dag-last-van-airbnb~a4496560/
- @Cinoreros:, I see where you are coming from and agree that this establishes notability on Dutch Wikipedia, but as per WP:NOTADICTIONARY, I struggle with this given it's nature as dictionary/thesaurus entry that is in its Dutch wording completely unknown and irrelevant. With new articles I often wonder, who will search for this, how often will this happen and how does this article link in with existing contents. Also, will this be searched for in 10 years time (WP:10YT). I totally agree this is an interesting phrase born out of advertising, but it would probably get more attention as part of the toilet duck article, if added there in a new section "In popular culture". pseudonym Jake Brockman talk 14:36, 23 June 2017 (UTC)