So far as I know there is no "proper" accepted way to hone these exactly. Most original documentation is pretty general, showing the washboard technique on a natural stone with slurry.

Personally I'm learning more and more about honing my Tosukes, they are very particular. And while I can get good results by doing what I've compiled between here and B&B forums, I get much better results by paying more attention to the asymmetrical grind. In other words, I find it's not as important to have the exact 2:3 ratio as much as it is to make sure the wedge side is ground down each pass. Very often with light pressure a burr builds up (on the wedge side) from stroking the hollow side within only 2 back and forth passes. I find that 3-4 passes are necessary on the wedge side to get everything to be in contact with the hone, but the problem is that it could be different for different hones. This leads me to conclude that the uneven ratio is not as much for keeping the razor even, but more for immediate function. I don't think if you use even passes that you would change the razor shape fundamentally, it just won't be as keen an edge as possible. Also I believe finishing on the hollow side gives a smoother edge as compared to finishing your last passes on the wedge side, my theory is that the burr is then aligned so that the hollow side towards your face is the most comfortable. You can hone it the other way, but this is one contributing factor to why you should only use one side against your face, and it does depend on how it's honed.

Once I get my chinese 12k I'm going to compile all my findings into one post that will hopefully be a good resource on how to hone these razors. Right now it seems most of the information available is fragmented and not all that accurate, at least for my razors.