In 1920, Father Eustáquio took over the work in the glaziers' colony in Maassluis, Netherlands, formed by about 700 Belgians who had fled the First World War.

He was appointed religious assistant to the workers of a glass factory who had moved from Belgium to Holland because of the war. Father Eustáquio ended up occupying this position because he was fluent in French, which allowed him to communicate with those Belgian workers.

Because of this work, the Dutch priest was decorated by King Albert I of Belgium for the religious assistance he provided. He managed to convert several workers who lived in the area, and to do so he had to be very forceful against the vice of drunkenness and other errors that those workers maintained.

In one of the testimonies given to the Tribunal for the Cause of Beatification and Canonization of Father Eustáquio, Father Gil speaks about the Blessed's dedication to the change of location, beginning with his own personal transformation:
“I note that Father Eustáquio stopped drinking wine, a resolution to which he remained faithful throughout his life, even when he was still assisting the Walloon (Belgian) workers; I am convinced that he made this decision as a self-imposed penance. Likewise, even before arriving in Brazil, Father Eustáquio gave up smoking for the rest of his life. When I referred above to abstaining from wine, I mean that he abstained from any alcoholic beverage..”