DIY fret file lube?

I've got an old diamond fret file that seems to be getting a little worn out.I've heard that a fret file lube product is recommended but I'm not much for buying a special oil that I might use once or twice in the coming years.Is there another,easily available [home depot] oil that does the same job without damaging a diamond fret file?

Sharpie ink? :mrgreen:

to clean the file:
brass brush and naptha
or
old toothbrush
or
soft eraser

any of these will work

Aha sharpie ink... Two birds with one stone!:lol:

to clean the file:
brass brush and naptha
or
old toothbrush
or
soft eraser

any of these will work

So, no oil recommended? Stew Mac sells it but I was just wondering if anything else is a substitute,or if nobody really uses it?
I do clean the file between frets with a brass brush.

Chalk

Olde engineers trick - ordinary blackboard chalk

^ Thanks!

files are typically cleaned with a brass "file card" and i prefer "pro cut" (stew mac) file lube to aid in cutting.