Don't waste your energy being bitter towards your Doctor. He or she just did what some stupid book told them. There's a lot of great people on this forum that can help you more than a standard doctor can.
From everything I've read, yes, you can do a liver flush. Why stop there, prove the doctor wrong. Do a Bowel, liver, kidney and parasite cleanse and watch everyone that continues to follow standard doctor's advise be sick all the time while you stay healthy. Everyone in my office teases me how I eat, my fasts and such. I find it a little annoying though sometimes when they call in sick all the time and I have to do all their work because I'm never sick. If the only disadvantage to all the flush's and diet is that i have to carry all the other's work load, not a bad trade.