In general I think that frequency generators are good provided that they are manufactured for use with the human body, but I do have serious issues with connecting the human body to a stereo or to a PC that is plugged into the wall. Contact the manufacturer of your stereo and ask what they think about it. I know for sure that they will give you a resounding NO! Don't do it!
The same is true for any PC manufacturer. There is a definite risk from connecting a PC to your body.
As for the Super Zapper Delux, I have talked to several people who owned one and have received both positive and negative comments about it. I would not buy it for two reasons. One is that I hear they got Dr. Clark in to more trouble than she would have been otherwise. The other is that I have heard at least twice that because of this, Dr. Clark does not allow it in her clinic. I do not know if these claims are actually true, but this is what I heard.
BTW, if anyone knows that these claims are not true, please advise me immediately.