My new Twister wing build is finally gathering momentum, but I don't want to botch the fitment by cleaning the excess charcoal with sandpaper. What's the best way to clean off the charcoal without removing wood? Or what about areas I'm going to CA, can the charcoal be ignored there? I'll be using thin CA in some places and 5 second Locktite CA in others.

For the outside edges, I just stacked the ribs and sanded them clean with 320 paper on a soft block. But the spar notches are harder to clean without removing enough wood to loosen the spar fit. I don't want to have to shim them after I lay the spars in place.
Rusty

As far assembly goes you can ignore the "charcoal", it won't hurt a thing.

I was worried about contaminating glue joints. Maybe it's not the problem I thought it was.

I remember when laser cutting started some of the guys said the burnt edges would weaken the glue joint, especially CA type glues.  I immediately proved them all wrong with the plane I was building at the time.   Now if you are doing transparent finishes a light sanding will take care of it.  But in ribs with cap strips,  just glue the cap srips in place.