I've had the parasites, heavy metals, and yeast to contend with. In my experience there are several things which helped me much more than the zapper that I might suggest:
1. colonics - This really has helped and I still get 1 per week. I couldn't believe the stuff coming out. Make sure you take pro-biotics if you do colonics.
2. Clay Packs - These block out interferance and let the cells in a particular area reset to your bodies resonance frequency and allow the cells to detox. These have helped greatly and reset all the merdians that got messed up from zapping.
3. NAET - This helped get rid of some of my allergies.
4. Heavy Metal Chelation - This helped, but I would not do without Colonics, it helps the stuff get out much faster. Also I recommend a slow and easy approach with breaks. I went into it a little to fast a few times and got major detox symptoms.
5. Raw foods - Carrot Juice, Garlic, Pumkin Seeds, Almonds, etc. All these seemed to help me. I'm not a complete Raw foodist, but I eating a lot of Raw foods, prob 70% of my diet right now.
I did try the zapper and many parasite cleanses with initial success followed by them coming back again. I had much better results treating the core problems and then my body killed the yeast and parasites by itself.