/vr/ - Retro Games

Just got my degaussing coil in the mail. Before I start, I want to make sure I don't screw things up. They say you have to use specific motions to degauss safely. You're not supposed to move the coil too fast or too close to the screen. How fast is too fast? How close is too close? If I screw this up how will it show on the screen? Is it possible to do permanent damage by moving the coil too fast or too close?

I bought a degaussing coil off ebay.
Before I use it I want to ask some questions.

Does the TV have to be on when I degauss it?
What happens if the TV is off?
Will nearby (a meter or two) TVs be affected by the coil in addition to the TV I'm trying to fix?
Will the speakers beside my TV take on a magnetic charge from the coil and have messed up sound?
My PC is a couple meters away. Will the magnetic HDD in the PC be corrupted by the magnetic field?