A few days ago, I suggested white drawing leads for marking dark wood for #woodworking but noted that I hadn't actually tried them yet. In the spirit of putting my money where my mouth is, I ordered a pack to try on a scrap of walnut. 12 leads for US$6.99, about $0.58 each.
Top part of the photo is the lead, bottom part is chalk.
They're ... meh. Not as good as I'd hoped. Slightly crumbly if you press too hard. More visible than my wife's fabric marking pencils, but not as good as chalk. Doesn't fill a knife line as well as chalk.
Could work, but chalk is probably better if you're OK with thick lines or fill a knife line..