I wonder if heating up some moly grease until it melts and then soaking some twine in it and allowing it to cool would work ?
Probably the messiest thing on earth to play with though !
You can get tallow , it is what soap is made of , maybe the same thing could be done with this stuff as above but using graphite powder ?
kieth appleton on his youtube channel mentione he un picked some larger diameter graphite sealing material to get the thinner twine to use in model steam engines , i never followed it up but if you could get the right stuff cheap it may be worthwhile fiddling around un picking the strands .
The stuff in my stuart kit looks a lot like a piece of yo yo string with graphite in it .