Direct sunlight yellows plastic.
Screw retrobrite. It's bathroom chemist bullshit. You waste time/money doing retarded crap and have to deal with that stupid paste you create which can give not-so-even results. It's also messy and stupid.
Here is how you retrobrite like a real human:
1) Get 40vol or stronger bleach developer from a salon. sometimes you need a license for the 50 vol. You can order "Urine Rescue" instead:
http://prolinesupply.com/cart/urine-rescue-p-154.htmlbut 40 vol. really will do the trick.
2) Get a 10$ 10 gallon aquarium for fish and crap. They are serously between 10 and 12$. You shouldn't need anything bigger for consoles. if you need something different, say for a 64C or other computer... go get a clear rubbermaid bin. I prefer the aquariums. You can be a cheapass and use a clear garbage bag and dump the stuff in. It works, but man, you better be careful that way or you'll dump burny peroxide all up ons.
3) Create a displacer of some sort inside the aquarium. That way, you use less peroxide. I usually lay the thing I am bleaching inside the aquarium and then stick a bunch of glass drinking cups face down all over the spare space. I also used some bricks wrapped in foil once. Don't just use bricks or anything dirty/pourous. It soaks the peroxide up and makes it cloudy and fizzy. Screw that.
4) Dump the peroxide in. Once it's completely covering the thing, you're done with that step.
5) Stick it in direct sunlight for a few hours, and laugh at all the morons who are messing with oxy clean and goopy whatnot.
6) When you're done. Save the tank of peroxide. it's reusable! \o/
**If you live in depressing places like England where there is no sunlight, you can go buy a 10$ UVB bulb meant for a lizard at the same pet store you got your aquarium at. You can also then buy a sweet 10$ sundome. The sundome has a reflective interior that extends the effective range of the rays.
Clamp it onto the aquarium using the clamp that came with the dome and aim it down at the glorious peroxide. Success. You can bleach your goods in your basement now.
I've bleached 1571's, 1541's, SFD-1001s, C64's, NES's, SNES, and all kinds of other crap using this method. I've used the same peroxide for a long time. I think I've had the same peroxide in the tank for a few years. Just keep it stored in a dark room with the top covered up. I saranwrapped the top.