>- but I've heard (a few cases) of people getting seriously incapacitated from the toxic die-off triggered by super-penetrating models. Perhaps a lower power is actually preferable from a safety standpoint.
That is absolutely right which is why I take issue with that particular zapper. I have heard several complaints about it. However, the main problem in the case that you pointed to is improper use.
Continuous zapping for less than 1 hour does not successfully kill enough parasites, so you will get new die off everytime that you zap. Zapping continuous for 40 minutes is asking for trouble.
>- As to quality, I think if it's functional, simple to use, portable, and fairly sturdy, that counts for something quality-wise, regardless of price or special attributes.
I agree, as long as it does not deprive the user of the best results.
Our 20 page manual cost us about $6.00 a copy to produce, ( about twice the cost to make a $10 zapper ) but is the most important part of what we sell. You rarely hear our customers come on this forum asking how to zap or complaining about bad problems. Our customers do not make the mistake of zapping only 40 minutes unless they do not read the manual.
Our copper footpads are very expensive, but we have only had 1 set returned in 3-1/2 years. We have a lot of customers buy the zapper first and then get the footpads a few of weeks later. They feel and see the difference and it is worth the cost. It is something that you just do not know about until you try it, which was my point to begin with.
Dual frequencies requires an extra switch and other parts which cost more as well as extra labor, but it is worth the additional cost to most because of the difference that it makes.
We include a low battery indicator in our better models because we recommend changing the battery before it gets below 7.5 volts. This produces better results. Some zappers draw a 9 volt battery down to as low as 5 volts. While Dr. Clark thinks that this is OK, it does not produce the best results.
Basically, while the $10 zapper may produce noticable results, you are not getting the best for $10. A lot is left out.