Yeah I just read the thread in it's entirety myself. I also have a Duo -R. The -R is white, no complaints there, could be a BIT whiter, but it's not bad. The controller on the other hand is YELL-O. I am interested in how this works out for you, you should do a before and after picture.
I also read the link about the SNES problem. Seems as though sometimes bleach may work, sometimes it won't. Seems that soaking them for a good day or so does the job. I think I am going to disassemble my controller as well.