I wouldn't bother with the enema, the epson salts are going to be taking care of the house cleaning. If you read on the package, epson salts are used as a mild laxative. You'll be sticking pretty close to washroom.
Trust me, it's the fear of the unknown today. Tomorrow, you'll be asking your self "Why didn't I do this sooner?"
Good luck, post your results, and if you have any more questions, we are here for you. I'm doing a flush tonight also.