I recently bought an old Woodstock stove (ca 1978-1979 non-cat model - looks like current Classic model, but without cat) and am getting it ready to install. I am re-painting the frame and re-grouting the joints inside. I removed most of the grout from the corners and where the stone joins the frame-- do I need to do anything as far as cleaning the stone or cast frame before I re-grout it (besides vacuuming out any loose dust)?