Hand Tools Archive
Natural Tomonagura is probably what you'd want. I'm having a very off day in terms of reading and writing, but I'll tell you a bunch of stuff you probably already know!!
* Botan, Koma, Meijiro etc. naguras that are marked are generally very expensive. They are intended to be used as a progression on a hard stone. I'd avoid them. There's really no practical reason to have them as they have gotten to the point that they're probably more expensive than buying small stones of various grits. Asano markings make for the most expensive of them, and I would bet there's a fair chance that there's a lot of fakes out there.
* Tomonagura, I believe, translates as "of the same stone", or something along those lines. The intention of that is to have a slurry on a stone that's similar to the base stone, which means these are the finest. In my experience, they are generally good quality base stones that are on the softer side compared to most large base stones. That's the case because hard stones don't shed their particles that readily, and nobody wants to pay 50 bucks for a small scrap of stone that is doing nothing.
* Diamond nagura (not sure why this term is used, you'd think it means a stone that leaves diamond particles behind, but it just means making a slurry of the base stone with a diamond hone). Preferable for the types of stones you're talking about - king 6k, 8k, etc, or any of the soft stones that are easily abraded. I suppose it's nice on hard ones, too. Some of them won't do much without being abraded. There's a whole debate here that I won't get into - but it's around the issue that a hard stone isn't that fine if you raise a slurry with its base particles, but they're usually expensive. ..
* Synthetic nagura - usually a more coarse abrasive than the base stone, and relatively cheap if you get it from a reasonable place - about 10 bucks. I prefer a diamond hone.
You don't really want to use a natural nagura with any of the stones you've mentioned, it's of little benefit since the stones are such strong cutters to begin with (relative to a hard fine natural stone). Best nagura with a belgian hone is another scrap of belgian hone. They vary so much, I couldn't say anything about what works best with each one - some of them are hopelessly coarse until they stop letting go of particles, so a diamond nagura isn't always a great option.
For your synthetics, I'd just use a diamond hone, though - leave the particles on the stone and use varying amounts of water, all the way to none if you'd like. Vary pressure (especially if you clear the slurry off the stone or let the stone dry) if you don't get enough variation from that.
One last thing. On stones that I've had that release particles too fast for my comfort, I like to use a slurry that's not that dilute and as it dries a bit over the minute or so of sharpening, let it go completely dry so that it glazes over and then finish the edge of the tool being sharpened. It will polish, but the slurry is still on the surface, just dried, and can be reactivated with water.
If you want to distill all of this drivel to one comment, I'd say get a piece of scrap coticule for the belgian hone (they should be about $20), and for the kings, just use a diamond hone and experiment. Avoid the expensive natural japanese naguras unless you're sharpening razors or using a fairly expensive stone that would justify the expense of a $50+ nagura.