Minecraft wiki entry for Cocoa_bean_farming, associated text: 1 Video
2 Farming
3 Mechanisms
3.1 Simple Water Flush Design
3.2 Wall design
3.3 Piston column design
3.4 Wall design with water
3.5 Bulky efficient design
3.6 Compact design
3.7 Water column design
3.8 Simple water flush design