I myself have never done a parasite cleanse, and have done 17 liver flushes, most of which i consider a success. Some people strongly believe in them, others think they are not necessary. Its really up to you to figure out what you are comfortable with.
I also did numerous flushes before I did a kidney cleanse. When I did, I was overdue and it was a bit rough on me. In my opinion, you could try a few flushes before you do a kidney cleanse, assuming you have no history of kidney stones. reasonable minds could differ on this though.