I was inspired to do some research and found the video referred to in the interview and his own Demi Demi website. The video is in a foreign language. It's worth watching to see the clothes he models.
His website is demi-demi.tk (English translation).
I also came across an article reporting on mugging he was victim to in 2007: original / English translation. In it, he is described as an ex-accordionist, singer and miniature builder and is said to ride a moped wearing a distinctive helmet.
This 2006 article from the same site is about his Demi-Demi clothing concept and also mentions his helmet: original / English translation.
This blog from 2008 mentions that he is a professional electrician: original / English translation.
There are two facebook pages dedicated to Demi-Demi: Demi Demi (Wilson) and De officieuze Demi-Demi Fanclub!