The epsum salts are a big question mark for me. ES pulls water into the colon and it's supposed to help you relax. But I tried it and it didn't work for me and I have seen many people get into trouble doing the flushes that prescribe ES. Things seem to get stuck in the common bile duct. You don't have to get too many phone calls at 2AM to see something just might be amiss with the ES flush. So I don't recommend it.
However, some people on this forum have had pretty good luck with combining my flush with the ES. So it's a variable. Try it both ways, with the ES and without. See what works best for you.
And my experience is just the opposite as what you've heard. The coke flush seems to get better results the the ES flush. And it certainly is a lot easier to do. None of this is set in stone though, so experiment a bit and add your two cents to this forum with the results you get. Might help someone else along the line.
Whatever you do, make sure it gets your liver back on line. It's important.