Ground loop eliminator - anyone use one?

Anyone use anything like the following to get rid of a ground loop:

Ebtech Hum X - three prong ground loop eliminator
Ground Loop Eliminator for AC Electrical Lines

or

Panamax MAX® 2 SUB

Thinking this would solve a problem I am having with waves on my tv.....

I used one briefly to kill an annoying hum my sub's amp has at exactly 60Hz (the same electrical frequency of many audio components).
Worked well...but I cut off the 3rd prong and saved a goofy connection later on.

you cut of the 3rd prong of the subs power cable?