"To do a detox" means to follow a specific plan or process to remove toxins or harmful substances from your body and improve your overall health. Full definition
If you haven't done a detox before or have a major imbalance you can expect the first few days to have some discomfort. (thehormonediva.com)
If you've never done a detox bath I recommend starting of with the basic ingredients and 30 minute soak time and see how you feel. (hairsprayandhighheels.net)