Yes you can opt for a four day detox diet. What are you trying to achieve? Do you want to get rid of all the toxins your body? Have you been drinking too much lately? A detox diet is very useful for getting rid of all the excessive toxins from the body. You can opt for a juice diet or a liquid diet and flush out all the harmful substances that are in the body. The only way to get rid of alcohol is to flush it out. Drinking plenty of water during the diet period is also another option.