greg mosser wrote:i feel like broomcorn would be a bit too thick.
i tend to use the pointy end of the file that lives in the middle of one of our fairly standard-issue fingernail clippers, myself.
I agree with both of these. Broomcorn has my under-the-nail skin cringing already. Yowch!
Fingernail anatomy varies, and mine is such that brushes do very little to get things out from under my nails- I use a metal tool, or the file in my army knife, etc etc.
We also use loofahs now for a lot of stuff and they're great. I wonder if you used the cut ends of larger ones (with stiffer fibers), if that would provide a "brushy" enough sort of texture to get under your nails?