I agree, use CA to fill in holes and seal the antler. Unsealed antler can turn a rather unpleasant yellowish color if it absorbs enough hand oil and other contaminants. I sand to 320 or 400, depending on how solid the finished piece is (more solid antler, higher grit, more marrow, lower) then drip some thin CA onto the piece while sanding it. This will allow the swarf from the sanding to combine with the ca and fill in the holes. repeat with the next section of your sandpaper until the blank is smooth and all pores are filled. Then sand with the next higher grit till all scratches are gone and the blank is ready to apply the finish coats of CA. I use med CA applied with viva paper towels, several coats, then finish as any other blank.