Can a plug adapter be used for 2 power cords leaving a power conditioner's receptacle?

AudiogoN Team,

Question for you all.  I have a system that has an integrated amplifier and 2 powered subwoofers in the main speakers.  This totals to 3 power cords.  I am looking for a power conditioner and I am seeing that many of these units only have 2 high current receptacles.  Is it ok to use a plug adapter that takes one of the receptacles and makes it into two for the subwoofers?  These plug adapters are commonly found at hardware stores.

Please provide your thoughts.  Also interested in what brands other than Panamax have power conditioners with voltage regulators that have more than 2 high current receptacles.

Thanks in advance for your thoughts.