Rob Stokes wrote...
Go with the shellac and sawdust. Mix it fairly thin and let it set up before
you sand it off and decide if you need another application. Sanding prior to
finishing will remove the shellac and "expose" the sawdust allowing it to
take a finish. It will be darker than the surrounding wood but should "tone"
nicely.

I have added corn starch to counter the darkening effect. Sand a couple
test patches to get the mix right, but it's often close to equal parts
with the wood dust. Bandsaw dust works great.

Jim