The article describes how the author hacked the detergent cartridge DRM system of their Bob Dishwasher, allowing them to refill the cartridges at a significantly lower cost. The author discovered that the cartridges use a simple I2C EEPROM to store the number of washes remaining, and by modifying this value, they could reset the counter and reuse the cartridges. The author also found that the detergent used in the cartridges is available for purchase in bulk at a much lower cost than the proprietary cartridges. By refilling the cartridges, the author achieved a 98% cost saving compared to buying new ones.