I don't have parasites so I don't do anything for that. I use Epsom Salts and/or Oxypowder for colon cleansing for a day or so after the flush. I don't do anything for my kidneys.
I should add though, that I've been cleansing for several years now and I eat a clean diet for the most part and only drink pure water. If I was doing back to back Liver Flushes I would do something for my kidneys I s'pose.