I have never used a Castor oil pack but they do get very good press and have a dual effect. Firstly the Castor oil works its magic but the process of physically applying the pack and visualising the gallbladder is also a strong psychological process. Some people report using one before and after a liverflush and say that the pack alone has been responsible for eradicating stones. It is also recommended that the packs are used in short burst, 3 days applying and 4 days resting.
My personal viewpoint is that one should only undertake one therapy at a time. Less is more when cleansing. This includes using a Castor oil pack as part of the liverflush but not using routine Castor oil pack therapy in parallel with a Liver Flush procedure.