Yes, I do colonics after every flush, and highly recommend it. I actually schedule my flush only when I have my colonics appointment set (been doing them for almost 2 years, if you have eczema, they are a lifesaver, cleared mine up). I would recommend to wait more than 12 hours after drinking the potion, that seems too soon. I do mine the day after the flush, e.g drink OO/GJ on Tuesday night, flush Wed, schedule colonics on Thursday.
Why do you only take 1 tsp of epsom? You may want to take a bit more.