Historic Plaster Conservation Services (HPCS) Limited of Port Hope, Ontario are often tasked with executing delicate architectural conservation tasks at scale. Here, they cleaned 15,000 square feet of original paint and metallic gilt on a coffered ceiling in the 1930 Beaux Art design Sir John A. Macdonald Hall. This gave them the opportunity to demonstrate just how effective TRI Funori is as a cleaning agent, removing 80 years of oily filth from the delicate ornament. TRI Funori, a natural extract produced from Japanese seaweed, is used with “washi”, a Japanese rice paper. The “washi” is held in place while the TRI Funori liquid is gently brushed through it onto the surface. After a short dwell time (established by field tests), the rice paper is stripped away, leaving the surface clean. If only all cleaning products were as effective, safe and well suited to their purpose as the TRI Funori washi poultice system.