After a series of early setbacks, Wong joined Hong Kong Rubber Manufactory Limited, a producer of rubber footwear and Wellington boots, as a sales representative. His diligence, reliability, and determination quickly set him apart, and by the age of twenty‐eight he had risen to the position of General Manager—his first major breakthrough in the commercial world.

As General Manager, Wong introduced sweeping reforms to production management, strengthened quality control, and placed strong emphasis on employee welfare. He implemented mandatory annual medical examinations, arranged on‐site consultations with both Chinese and Western doctors, and established a dedicated fund to support staff in times of need—measures that were progressive for their time.

In the years following the Second World War, Wong met Pauline Chan (Chan Chiu Kam), who joined the company as a secretary. Fluent in several languages and highly adept in negotiation, she was rapidly promoted to Business Manager and soon became an indispensable partner in Wong’s business endeavours.

In 1947, Wong and Chan co‐founded W. Haking & Company Limited, engaging in the import of overseas products, including British fashion goods and Australian wool yarns, while also investing in film ticket distribution and advertising. During an industrial study visit to the United Kingdom, Wong was struck by the efficiency of toothbrush tufting machines. On his return to Hong Kong, he oversaw the successful local replication of forty such machines.

Together with Pauline Chan and his elder brother, Wong Chiu Lee, Wong established W. Haking Industries (Brushworks) Limited. As market demand surged, the company built its first factory on King’s Road in North Point. With daily output reaching 250,000 toothbrushes, it became one of the largest toothbrush manufacturers in the Far East, earning Wong the sobriquet “King of Toothbrushes.”