This production line washed, dried, dipped, (in a oil based dye), and Freon de-greased ceramic parts for final inspection. The dye penetrant would leach out of any cracks or chips, easily revealing defective part.
Before this line was automated, labor costs were high and working with the dye was extremely messy for operators. Not only did this project have a 10 month rate of return but safety and ergonomic issues were eliminated. The operators were also very thankful to no longer be involved with such a messy manual process.