Why Earth-Grounding?
On its own, earthing is also relaxing.  Also, earthing typically improves sleep; and increases one’s resilience against physical stresses.
Read more about earthing at The Bulletproof Executive:
http://www.bulletproofexec.com/earthing/

How?
Earthing products involve either a grounding rod or plugging a wire into the ground/neutral terminal of an electric outlet and connecting that in some way to your body.  This might sound dangerous — no doubt it could be, in a thunderstorm.  I don’t supply a special earthing gizmo for The Whole Body Vibrator.  All you need is a wire.  What I use is the “Plug to Gator” at the link below:
http://www.lessemf.com/ground.html