I am finishing a walnut guitar and am using Tru-Oil initially to darken the wood's color. After a planned 6 coats or so of the Tru-Oil, I intend to finish with lacquer. I am buffing with steel wool between coats of the Tru- Oil. My question is, after the last coat of Tru-oil has cured for a week or so, can it be wetsanded with 600 grit to prep for the lacquer? Or should I only buff with the steel wool?