Won't do anything.
Power factor is important when you have highly inductive or highly capacitive loads. These loads will time shift voltage and current. You'll still pull the same voltage and current, but they'll be out of phase, the net power over time will be lower.
The most important thing to remember is that home utilities meters don't change billing based on power factor. Thus, while this device could help with pf, it won't change anything on your power bill. Only bigger industrial or manufacturing plants are charged for pf !=1. Power companies also have to watch power factor on transmission lines.
So, the theory is correct, but it doesn't apply to residential homes.
Hope that helps. It's been about 15 years since I graduated from my EE program. And there's a bit of bong resin clogging up some of my neurons...