There is something here:
http://home.comcast.net/~gionpeters/hhhh/duo.htm
... if you scroll down.
In the past, I planned to give a really bad Duo keyboard such a going over, and thought of using a product called "Rubber Renue" (which really does work well on old rubber) along with cleaning, etc, but then I came across a Rev. F keyboard and did not need to go to the trouble. The dysfunctional keyboard is now in the parts box. I have three Duos and all keyboards seem to work fine.
They also improve with use, in my experience, which once included a fair bit of banging on the keys. This suggests that the website has it right and that simple friction can clean the contacts.
http://home.comcast.net/~gionpeters/hhhh/duo.htm
... if you scroll down.
In the past, I planned to give a really bad Duo keyboard such a going over, and thought of using a product called "Rubber Renue" (which really does work well on old rubber) along with cleaning, etc, but then I came across a Rev. F keyboard and did not need to go to the trouble. The dysfunctional keyboard is now in the parts box. I have three Duos and all keyboards seem to work fine.
They also improve with use, in my experience, which once included a fair bit of banging on the keys. This suggests that the website has it right and that simple friction can clean the contacts.