Definitely do the juice with the Epsom Salts . I use fresh pressed apple juice, and it's great. However, the ES still has a very strong chemical taste. I use a straw to drink the mixture, and put the straw as far back as I can without gagging. Drink fast, and then follow with a tiny bit of juice.
I actually don't mind the grapefruit juice/olive oil mixture.
I'm getting really excited! Wish I could do it sooner than Monday, but it's not worth doing if I'm not going to do it right. That includes proper preparation. I even bought a garage sale colander for the toilet ($.25), so I can throw it away at the end!