To start with, you'll need the following materials.
> Heavily unreadable scratched CD's
> Cloth (Any cloth will do, but preferably cotton or the ones used in eye glasses)
> Small Plate
> Ajinomoto or Monosodium glutamate (MSG, used to flavor foods)
> Cooking Pan w/ 1 cup Water and Gas Stove
> Dry Towel
> Dishwashing Soap
Step 1: Pour in the Ajinomoto MSG and water into an empty plate.
You can add soap into the mixture, to easily speed up the polishing, since MSG is water soluble, you can have any variations with it.
Adjust it to your desired effect. THE MORE WATER, THE MORE FINE FINISH, THE LESS WATER, THE ROUGHER IT GETS.
Use less water to scrape off deep scratches, then add more water later to a fine finishing.
Step 2: Start scraping.
Using your thumb, scrape away the CD plastic from the center outwards then back again..
You can also do a clockwise and counter-clockwise direction or x-hatch, but do the scraping as fast as you can, till you get a mirror polish.
As you can see in the third picture, the CD's plastic is easily scraped in just 6 seconds.
The deeper the scratch is, the more pressure and MSG you would need to apply.