Hey, don't worry. I just did my first flush a few weeks ago. It's less dramatic than you might expect. I had a bit of nausea the following day, but it was gone by the next day, and then I felt great in a 'whole body' type of way. I didn't take any of the other herbs -- just drank apple juice for a few days before -- so you're more prepared than I was. Don't take any herbs or medicines the day you plan to start the flush.
The next morning (after the evening you've had the Epsom Salt series and oil / lemon juice), just plan to be within 'dashing distance' of a toilet until late afternoon or early evening (if you're still 'flushing' it through).