In June 1939, Walaszczyk was taking part in the military preparatory course near Lidzbark Warmiński. After the Germans invaded Poland on 1 September 1939, he was mobilised and sent to Brześć, Eastern Poland. When the Soviet Union attacked Poland on 17 September 1939, Walaszczyk and his cousin, who also was sent there, decided to return to Rylsk instead of going to the Romanian Bridgehead, which was their initial idea. Despite difficulties (Józef was arrested for a couple of days by Germans), they reached Rylsk at the end of September. In December 1939, thanks to his knowledge of German language, Walaszczyk was appointed as manager of the factory and as administrator of the whole estate in Rylsk. He was employing around 200 workers including his family, friends and others in the community (including Jews), providing them with food and accommodation. Most probably in 1941, one of his friends made before 1939, Wengrow, asked him to employ forty Jews from the ghetto in Rawa Mazowiecka. Walaszczyk agreed as he owed him a favour. He got permission from Miller, head of the local Arbeitsamt (labour office), convincing him with a large bribe to get 30 Jews. Walaszczyk needed to bring another installment of the bribe every two weeks. Hired Jews had a good enough situation to take care of themselves, so Walaszczyk did not need to feed them. However, after a dozen months, Miller withdrew his permission. Walaszczyk advised his workers to hide if the Germans appeared. When he was on his way to the Arbeitsamt, German officers appeared at the estate with trucks. A couple of Jews who had not hidden, were arrested and transported to the ghetto in Łódź. The rest hid and survived.