Two physical grounds??

Try running a #14 awg to the outlet that your power conditioner is using, to a cold water pipe and clamp off to that. Swap out the old two wire outlet to a new three wire grounded outlet. The NEC allows for this and will provide an equipment grounding conductor for your conditioner. You can also run an addition wire to a driven ground rod if you would like. Don’t have any idea where the neutral (grounded conduction) receives it’s ground reference and might result in noisy ground loop, if so you can buy various products to combat that and the conditioner is much safer with the grounded outlet. Good luck. T. J.

With all due respect Gs556 should not be giving electrical advice.

"The solution is easy provided you have a metal outlet box. Simply buy a 3-pronged outlet and a package of green ground wires (pre-looped, and with green screws, called 'Equipment Bonding Jumpers'). Remove one of the old two-prongers where you want to install the PC. Install the new grounded outlet to the white/black wires and install the green ground wire to the ground screw of the outlet. At the other end of the green ground wire, screw it to the metal box with the green ground screw. Push the wires back in the box and attach the outlet to the box. You now have a grounded outlet."

No… you now have an ungrounded circuit terminating to a grounded outlet. The exact same as a two wire ungrounded outlets but now not compliant with the National Electrical Code or most International Codes.
T. J.

Jea48,
Check this from the 2011 NEC. 250.130(c)1
250.130 (C)
(C) Non grounding Receptacle Replacement or Branch
Circuit Extensions. The equipment grounding conductor
of a grounding-type receptacle or a branch-circuit extension
shall be permitted to be connected to any of the following:
(1) Any accessible point on the grounding electrode system
as described in 250.50
(2) Any accessible point on the grounding electrode conductor
(3) The equipment grounding terminal bar within the enclosure
where the branch circuit for the receptacle or
branch circuit originates
(4) For grounded systems, the grounded service conductor
within the service equipment enclosure
(5) For ungrounded systems, the grounding terminal bar
within the service equipment enclosure
The cold water pipe is part of the Grounding Electrode System. The key word is System, which includes the cold water pipe. Check 250.50 for description of GES.
This is discussed in length on Mike Holts web site.
As far as the correct size of the equipment grounding conductor for 15amp circuits #14awg copper or 20amp circuits #12awg as per 250.122 2011 NEC but nothing wrong with #10 also.
Did not mean to slam GS5556 but a blanket statement like that can get people hurt. Peace T. J.

Agree with Magfan. Good advice. Hire a Pro in your area :^).

Jim,
I just checked the 2008 hand book:
This 5-ft limit also applies to the replacement of nongrounding receptacles with grounding-type or branch-circuit extensions in accordance with 250.130(C). See the commentary following 250.130(C) and the illustration that accompanies that commentary, Exhibit 250.51.
I stand corrected. Not the first time! Peace T. J.