There are different protocols, so you will get different suggestions. I don't use a zapper and once in 2 years I did a parasite cleanse. I follow Andreas Moritz and he does not see a need in parasite cleanse as long as you keep the bowels and liver clean. So in general I try to eat right for my body.
Other protocols suggest parasite cleanse, but if you already have done it you don't have to it again. The liverflush also gets rid off parasites.
Andreas suggests colonics but other protocols don't. If you don't just make sure you use the Epsom Salts to get the intestines clean. A lot of people ,who don't want to do colonics (expensive), do a couple of enemas instead.
Keep reading the FAQ at the top of the page.
Good reading is also Julia Chang's website http://www.sensibleheath.com