Start with a cup of Epsom salts and a pint bottle of hydrogen peroxide if you want some extra oxygen. Work up from there. I've never used baking soda in the bath... I assume it's fine, I just haven't done it so I can't tell you how much to throw in.
These detox baths are so incredible. When I have more time I'll share some of the benefits I have experienced personally from doing these. They are kinda like mini- cold sheet treatments... same idea with a little less intensity. I've been doing them "almost" every other night for over a year.