Basically, the way it works is due to all things having thier own frequencies.
By using a bottle copy of say, the herpes virus in a particular tissue such as the liver, for example, and checking your body for the same exact frequency using the zincrmeter, you can find where the herpes is approximately located.
This can be done with almost anything including metals, toxins and parasites.
I am in now way, an expert about it but this is the the basic understanding I got from Dr Clark's books.
If anyone else out there can explain in more detail, please jump in...