I like bark. Comes in a variety of colors, stores easily, can be used as flakes stuffed into broader areas, or ground in a coffee grinder to the consistency desired and looks as if it belongs with wood.
Stage your repair for best results. If the crack is wide open, thick consistency CA and bark flakes stuffed parallel to the edges and tamped with fine ground is good. Big flakes will absorb finish instead of mocking you with their shine and rejecting other finishes.
Tighter cracks get a run of thin CA first, then a fill based on thick if the crack is substantial, a second shot of thin if small. I always put the glue in and scrub the fill across the crack, leaving it proud of the surface. Stuffing and then gluing produces the same plastic streaks I mentioned above.
Coarser textured material, like the coarse dust produced while cutting end grain gives less of an opalescent walleye look to a sawdust fill if you're trying to sneak one by. With spalted maple, the natural fill would be black to look like spalt lines in the fine, or splinters bordered in black.
