Green Soap in large size 1 gallon bottle. Green Soap is a soap that is generally not available in retail stores. This stuff is a great multi purpose soap for this industry. Green Soap is normally diluted to make it less concentrated so it is more easily rinsed off or does not leave as much residue to cleaning areas. Diluting green soap will generally not affect its ability to clean, unless you dilute it way too much. It is best to use distilled water with green soap to dilute it.