Stripping paint is a tedious and difficult endeavor. All too often, amateur do-it-yourselfers successfully strip away surface paint, only to find lines of paint embedded in the grain of the wood. Rather than giving up, and living with the trace residue because you simply have no idea how to remove it, you can remove paint embedded in wood grain if you know the proper techniques. Be patient; the process can be painstaking, but the result will be a professional-looking paint job.
Dampen a rag with mineral spirits.
Wipe down the paint in the wood grain with the dampened rag.
Scrub the paint with a plastic coarse brush. Scrub along the grain and not against it.
Dampen a second rag with mineral spirits and wipe the paint in the wood grain again.
Rub the paint residue with 300-grit sandpaper, going along with the grain and never against it.
Scrape any remaining paint out of the wood grain using a dental hook. Work slowly and meticulously to avoid gouging the wood.