RE: what removes residue from balsa
One thing, acetone is also the solven for CA glues. As long as you dont soak the wood, IE submerge it in a tub of aceton, lol, the glue is not affected if you are just giving the wood a quick wipe with a damp rag. I recently glued a some parts together backwards and successfully soaked the balsa to release the glue completely. I also use it to remove extra glue as in when I edge glue sheeting. A wet rag will remove unwanted glue form the surface making sanding easy.
Randy