If you do want to go for a pemf, make sure you get a full body mat, the coils works like the magnetic pulsar so its no use to upgrade just for that, you won't gain anything. But if you use the whole body mat you will get the best results.
But like the other posters recommended, there is cheaper and better options for your condition. The reason Bob Beck build the Magnetic pulsar, was to clean the lymph nodes, to break up any tumors or what ever accumulates in the arteries. It works very well with kidney stones, unfortunately if the stone is to big and it comes of you have to go on the operating table. But he also used the blood purifier because the magnetic pulsar wasn't enough. Plus he used Ozone and Colloidal Silver . But anyway the PEMF is designed to work exactly like the magnetic pulsar only stronger. The reason ( and this is my educated opinion ) that you feel it helped your skin condition, is because of better blood circulation the body could now take better care of these parasites. Now this is a good thing, and again if you use the body mat your whole body will be able to function a whole lot better. If your body is working at peak performance, parasites don't stand a chance. I am anxious to see jaguar's reply on the Hydrogen peroxide. But normally skin problems like this is a indication that there is something else wrong along the way.