I just another bleaching the other day and thought I would post results
Super Famicom Peroxide Treatment by xelement5x, on Flickr
I recently did a peroxide treatment on an extra Super Famicom I had laying around as I continue to try and perfect the process. This one was kind of moderately yellowed in the beginning, but nothing overly atrocious.
I used a small transparent plastic storage container, plus 1 gallon water and 32oz 40vol Peroxide from Sally Beauty, then soaked each half for about 2 hours on a nice sunny Colorado day.
The final result is quite nice in my opinion, it looks practically new except for a couple scratches on it that are barely noticeable.