Replacing generic RECEPTACLES

One useful cheap tool to use in the ever exciting world of AC power is a "GreenLee GT-16 Adjustable Voltage Detector" They now cost about $23 on Amazon. (Other brands do not work as well for sniffing stray AC The GT -16 has a good adjustable range, and works well for AC) Once you have one, you can sniff out all the stray voltage escaping from your AC wires, plugs, and equipment screens etc..So odd things too, Like pole lamps spray a ton of AC contamination.. When the basic zip cord in running up inside the metal lamp pole.. Another place are umbilicals of two box preamps. I own two of them And both umbilicals spray a ton of 300V stuff (Both use tubes)
ALL AC outlets spray electrons out the unblocked holes..
One of the reasons I still like Pangea power cords is they are REALLY well shielded. No stray voltage there. *except atthe molded plug ends)
So with the GT-16, I can see I stop all the stray voltage out of a duplex with the brass plate. (if the holes in the duplex outlet (for plugs) are filled with metal body grounded plugs.
That is all you are doing with the Carbon Fiber one too.

I also find the Teflon plumbers tape tweak to stop the escape of stray voltage from duplex.
That is wrap each AC plug 3 metal prong bases with a few turns around each prong base with the tape. The plug, when inserted the duplex will push the tape and crush it between the plug and duplex, creating a insulation shield where that small space of blade is exposed... so the sneaky electrons do not sneak out the crack. naturally I cannot hear any difference with this. But it is a dexterity challenge, and fun to mess with. One time added and usually the Teflon tape will stay in place over several pluggings. and unpluggings.
Complete waste of time, but for fanatics... Nothing is to obscure or odd.

@elizabeth ....Thank you for your explanation on the Brass outlet covers...I am going to take you opinion and fly with it...Thank you for saving me about $ 615, on those 2 carbon fiber covers from Oyaide. I will now use Brass dual duplex , and a Brass single duplex with my 3 Furutech GTX-d r 

@folkfreak    Thank you for sharing your experience with the Oyaide plates and covers..I really am glad now that i didnt buy them ..

Remember to get solid brass, and not brass plated. Usually the brass plated will say brass plated steel...When you get then, (to be certain) just test them with a magnet. Brass will not attract the magnet. The brass plated steel will attract the magnet.

Just for the record, not intending to judge too harshly, ceramic wall outlet covers sound much better than brass ones. But not for the reason you think. It’s also partly why ceramic feet/cones sound much better than brass ones. Hint: it’s good old physics. And it has nothing to do with magnetism.