Desire a whitewash stained look on oak that has been previously finished. Appears to be finished with a minwax type oil stain. I was considering using shellac to seal it consistently, but not sure what to follow it up with. As a last resort it could be painted, but a solid white appearance is not really desiored. It's a large QTY of wainscott in a house. Stripping wood is not really an option. Any suggestions?