I've gone thru mag bleaching two times. First a set on OGK/Performer mags and a set of Tuff II's.
Here's what i did, i hope the pictures will speak for themselves cause the actual article exists only in finnish:
Performer/OGK's was the first bleaching project and it was succesful:

The Tuffs:

At this point i had only washed the excess dirt/grease off:

A sink made of cardboard and plastic bag and some textile chlorine, a brush, some ceramic polisher and a bar soap. I added bleach liberately, say about 1/4th of bottle. Make sure to wear rubber gloves!

Mag #1 in bleach. Okay, this first photo is more yellowish than others because of indoor lighting and bad camera maneuvering but yes, they were still far from white:

After soaking for 2-3 days you begin to see the difference:


The final wash up and rinsing:


The final result:
