a friend of mine took lemon juice, and she said it was much more nasty than with grapefruit juice.
And like Hanna wrote, me too, I couldn't eat olive oil in salads anymore. But after i bought a better/lighter quality, i really like it again.
My last 2 flushes i did with rape oil. The next flush on next saturday i will try almond oil, seems to be the one with the less taste.
Dr. Clark writes, that you can drink the mix within 10 Minutes. If you can't tolerate the whole amount, then i would reduce it. This seems better to me than throwing up the 150 ml.