wilbur
I'm reading between the lines a bit since you weren't explicit, but it sounds like you're talking about a dai with a bit of twist to it. There are many ways of doing this, but at the end of the day, it's a piece of wood, and you want to get the twist out. I bet you already know how to do that.

Don't rule out winding sticks just because it's a relatively short distance. They work great for this purpose. You can also just stick some relatively fine grit sandpaper to a known flat surface and take out the twist that way. The benefit of using winding sticks is that you'll have a bit more control over the process than the sandpaper method.

Also, don't worry about screwing things up. The worst thing that can happen is that in the process of removing the twist, you remove enough wood from the sole so that the blade protrudes farther than you want. In that case, you can glue some paper to the bed of the dai, which will cause the blade not to protrude as much, or just grind down the excess projection on the blade itself to get rid of the extra length.