The Epsom Salt solution (Yuck!) tastes much better with grapefruit juice.... and for this one,it does not need to be freshly pressed. For the mix with ex- virgin olive oil however it must be freshly pressed.
You could use lemon or grapefruit juice, both work well, but for some reason, you must not mix the lemon with the oil, but drink them alternatively instead. Anyhow, the grapefruit never was a problem for me.
As Alex said, antioxydants the day after, and an enema is also a great idea.