Here's a little trick that works for me to avoid nausea and get to sleep fast when flushing.
For a few days before a flush I keep a pad and pen next to my bed. In the morning before I get up I jot down any dream I remember. Then right before I flush I look at the pad and pick out the most entertaining or interesting dream. After drinking down the oil and juice mixture I get immediately into bed and suck on a peppermint altoids. The nausea is mostly psychological and so I just DONT THINK ABOUT IT. If I lay there and think about it I would feel sick. So, I think about the dream. I try to remember it in vivid detail. This serves two purposes: first, it takes my mind off my belly full of oil. Second, it ushers my mind back into dreamland and as my attention goes fully back into the dream I usually fall right to sleep. I learned that trick when I used to have insomnia.
Hope this is useful to someone!