All the power factor controller does is reduce the voltage to the motor until it is running at maximum load for the applied voltage. Is the power company giving a reduced rate for this? Otherwise there is no point because you don't pay anything extra for low power factor, normally. There is a power factor circuit at this URL: **broken link removed**
Russ is correct . PF "black boxes" are nothing but HV caps to align leading or lagging current/voltage ratios . They are used in factorys to keep electrical costs down. As for home or single use applications application buy an energy efficient appliance.