Zapper, has anyone used this device?

I have a question, have any of you heard of Zapper?
Has he had any experience with it?
What do you think about this method?

In short, it is a device that generates specific electrical voltages to combat various diseases caused by bacteria, viruses, fungi and parasites.
Appropriate voltages are set on the device to eliminate specific viruses, bacteria, fungi, etc.

There are many positive statements about it on the Internet and it is said to be backed up by some research.
The device and method are described in detail in the book "Dr. Clark's Cure of Life".