Some people use apple juice to dissolve the Epsom Salts in, rather than water or grapefruit juice. If you are asking about mixing the olive oil with grapefruit juice, you can use lemon juice instead of grapefruit juice. Most people drink the oil and lemon juice separately. I mix them together just like the grapefruit juice and it works great. I also sometimes use the juice of one lemon and grapefruit juice with the olive oil, all mixed together and that works very well and the lemon juice seems to be the predominant flavor. The purpose of the citrus juice with the olive oil is two fold. 1) It helps emulsify the oil so it isn't icky oily when you drink it. 2) The sour flavor somehow stimulates the bile flow.