Wire Ducts: First attempt failed

My project this weekend was to start installing turnout lanterns and the wire ducts needed for a mechanical interlocking ("Mechanisches Stellwerk" in German). The lighted lanterns are from Maerklin 7547 and simply click into the K-track turnout. Very slick.

While the lanterns will look very cool once the covers got some weathering, my attempt to build the linkage wire ducts from coffee stirrers failed miserably. I was willing to overlook that they are a bit oversize and too smooth, even when painted. The coffee stirrers look reasonably believable with a coat of primer and a rust wash.

But, the color doesn't stick to the plastic reliably, and can be easily scratched off, so if I were to install these on the layout to simulate ducting, I'd destroy half of them already when gluing them into place and run the risk that any derailment, track cleaning, or fat fingers, would scratch the color off. Not even talking about that I'd still need to build roller boxes somehow. While they could be 3d-printed, I ended up ordering the respective well-known Weinert parts.