The Epson salts needs to be pure, dried and for internal use. The small tubs that are available at a pharmacy meet these requirements.

Other Epsom Salts are specifically formulated for baths and are sometime pure but not usually dried. These are also suitable but double check for purity.

There is another group that are for swimming pools and garden fertilizer and these often contain impurities so they are no good for the liver-flush.

This picture illustrates the ideal type which was obtained at a pharmacy (aka Chemists) in the UK.





You don't need the HCL