Sensible health liver flush question

I have a question regarding the flush on sensiblehealth.com which doesn't use Epsom Salts unless necessary. The flush is located here - http://www.sensiblehealth.com/gallbladder.html.

Now, the flush says to do a salt water flush the morning after but also states that lemon juice can be substituted for the salt water. I'm wondering how lemon juice produces the same results as salt water.

Also, is it fine to do the Liver Flush sans Epsom Salts , or at least with less than 4 tablespoons of salt. The taste of the Epsom Salt mixture is very difficult to take.