Soooo, anyway:
![Image](http://i.imgur.com/g6PIgK5.jpg)
(To be honest, it removed the dirt very efficiently.)
Now here is the question. What is the best way yo fix it? I am quite certain I will have to wipe it in between the traces since I might otherwise short a few of the traces with the smudged conductive stuff.
Conductive ink
I think this runs a great risk of just getting rubbed of in the connector which is sort of mechanically abrasive to a relatively weak conductive ink. The coating might not be very flexible either and break up unlike conductive ink used on for instance a hard PCB.
Conductive tape
If I use tape which is only conductive in the Z direction then I might be able to just put a strip over it all. 3M has a quite famous such tape. Since the ribbon cable is single sided, all I really need is a conductive tape with conductive adhesive and I can cut thin strips and tape them over the edge. This will provide some mechanical durability as the tape can't be torn of ass easily by the connector. I might need to replace it each time the cable is unplugged, but that shouldn't be commonplace anyway.
Something else?