Not really, any finish has to coat the part of the bean that is exposed to air, or it will dry out and crumble, besides enough resin has probably soaked in so it doesn't smell like coffee much any way.
John; I find that after finishing the blank, and before assembley, I just touch the ends to the disk sander. This leaves a raw unseen edge that lets the aroma come out. And as stated above, there is so much resin in the blank, you don't have to worry about moisture getting in. Jim S