-am a little too hot n sleepy so i hope i make sense-
slices of horn will be solid all the way, only the core of the horn can be hollow or softer and cleaned away.
You shape it with a saw and/or dremel and sandpapers
no you don’t have to wet it, but it helps in sanding to dampen it slightly to reduce the dust, BUT it leaves the surface slightly fibrous and you’d need to dry sand after to smooth it down.
the blade part can be made like i did; cutting out the outside shape and sanding down and cutting from there to get the thinness (a good power sanding is almost essential),
OR you can split the chunks down more than i did and insert it into a wood handle before the final shaping.
OR
you can cut the wood and horn in rectangles, laminate together and then cut out your bachi in one go.
it’s down to your imagination.
horn was so interesting to work with, it’s kinda like plastic, you can cut it very thin and heat bond it together, you can boil it in water to make glue, you can heat it and bend it and allsorts.