I tried it with the lemon once and couldn't drink it.
So I don't use it.
You can use either Coke of grapefruit juice. They both do the same thing.
I switched to Coke a while ago because I found that I could get down more olive oil easily.
I am going to try the grapefruit juice again next time to make a comparison.
If it seems I can do as much oil, I think I will stick with the grapefruit rather than put the Coke into my system.