The Xpower device was heavily marketed as a power factor reduction device and was supposed to save you big bucks on your home electric bill. Unfortunately most residential customers aren't charged for power factor... This is only measured for commercial and industrial customers.
My wife saw an income opportunity and bought several of the devices. It's hard to say if they worked or not since residential power demands fluctuate daily. One day, after a few years the light went out. Being curious about Mr. Dockery's "engineering", I carefully sawed the cylinder in half. The only components inside were a D-cell sized capacitor with a resistor between 2 of its terminals, the neon power indicator, a fuse, and the power cord. There was nothing to justify the $80 cost of this device. Mr. Dockery, as I tried to tell my gullible spouse, is a charlatan and rip-off artist. I'm glad I prevented her selling this "magical devie" to any of our friends!