The first three times I did a Liver Flush I used organic cold-pressed olive oil mixed with fresh pink grapefruit. No problem.
The last time I flushed, all I had was regular light olive oil and it was all I could do to get the mixture down. Never again. I thought it would be less tasty, but it was just the opposite.
I'm sticking with the organic, cold-pressed stuff from now on. But everybody has to experiment with what works best. You'll be doing it enough to know what that is for you.