black crayon.
I've finished forests of teak, and many other exotic woods, and all the nail holes associated with it. My nail patch kit is a selection of expensive crayons - literally tinted wax.
You can heat a pin, and drip it into the damaged area, smear it in, blade it in.
If you overfill, scrape it back with a razor blade, pulling the blade backward, not cutting into the patch.