This is all that I can discover. It isn't much, but I hope that it may help in a small way. This is an extract from a Dutch book that shows photographs that were taken during the war. One particular photograph shows Dutch men on a train that would take them to Germany, in August 1940. The caption says this:
Dutch workers at the Amsterdam Central Station depart for Germany, to work in industry. The first contingent of workers was entirely made up of volunteers. It was mostly unemployed persons who sought their fortune in Germany. German propaganda did everything to give a positive image of the living and working conditions. The taking up of work in Germany took place, initially, on a voluntary basis, but very quickly more and more pressure was put on the unemployed to accept 'suitable' work. If anyone refused to do that, their unemployment benefit was withheld.
Het 40-45 Boek. Waanders Uitgevers/Collectie NIOD. Erik Somers, René Kok. 3rd edition 2005.