Create a mixture with one-half cup washing soda, one-quarter cup white vinegar, 2 tbsp. lemon juice and one-half gallon lukewarm water. Stir the ingredients until they are well incorporated.
Dampen a kitchen sponge with the mixture and begin to wipe down the pine tongue-and-groove walls. Use overlapping circles and apply slight pressure to remove streaks and stains.
Dip a plastic scrub brush into the mixture and use it to remove any difficult stains. Work the homemade cleaner into the stains, paying attention to avoid scrubbing hard enough to remove the wood’s finish.
Dampen a separate kitchen sponge with plain water and wipe down the pine paneling to remove the soapy residue. Use a microfiber towel to dry the wall and prevent streaking and water marks.