Before/After of retrobrighting my breadbin keys. It can be done!
How I Did It
First I removed the keyboard from the Breadbin (which came with a cracked case in 3 places, and doesn't boot. Ebay really sucks sometimes. I did get a partial refund at least...). I then put it in the dishwasher and used 1 cleaning tablet. This doesn't hurt the keyboard as it has non-corrosive cleaners (that's why our silverware doesn't corrode, too).
I put it on 1 single wash cycle, and turned off the drying. Just a nice wash.
Next I got a Q-tip and some 40 volume salon creme. Something like this
I dabbed the creme onto the white letters and numbers. Then to trap the gases, I wrapped the keyboard in saran. Then I put the thing in the window. We've had gray skies and snow here the past few days, so I left it over there for several hours. Today we had sun, so I moved it to a window that was getting a lot of sun and producing some heat. Heat is a good thing.
Then I took the saran off and cleaned the top of each key using paper towels and rubbing alcohol.
Here are the results. It's not easy to fully appreciate with this photography as the exposure is a bit too high with the yellow version - but trust me when I say it's noticeably dramatic.
The "F" keys still aren't perfect, but this is good enough for me now. I can always do it again some other time - and probably will, as the affect is not permanent. But it's a hell of a lot better than where I started.