Hi Serina, welcome to the forum! I'm so glad you're enjoying it. :)

Okay, while some people go right into the Liver Flush from a fast, I'm all about feeling good while getting better, so my guidelines go like this:

Break the Master-Cleanse fast with your most comfy juice (Not everyone can tolerate OJ), broth, spicy teas (to wake up digestion, very necessary after a 3+day fast! - see post on teas in FAQ), then steamed veggies, kichadi, easy things to eat. Be sure to take in a bit of oil to prime the gallbladder.

Start, 3-7 days before liver flush, dissolving the stones. You can do this with apple juice; malic acid supplements; liquid phosfood (very cheap and effective!); herbs. (see Liver Notes)
also cleanse the intestines best you can with colonics, fiber, whatever you can do.

Flush, preferably using 2 doses of oil/juice so you can stop if you need to, feel really awful. Consider using less Es than the Clark recipe calls for, it's an awful lot of Magnesium!
On day following flush, do a colonic or salt water flush. Eat only foods off previous list.

As for parasites, if you don't fit the profile of someone who might have gotten them (foreign travel, work wtih children, walk barefoot in dirt, own pets) then don't worry too much about worms, but do the questionnaire/self-test for candida, which is quite prevelant and doesn't require an entire parasite cleanse, just an anti-candida protocol.

Hope that answers your question! :)