To remove scratches, dents, and grooves, sand down wood countertops with sandpaper and follow up with food-grade mineral oil. Only natural cleaners should be used on wood, but as an alternative, you can use dish soap and a sponge, then disinfect it with white vinegar for 15 minutes, and lastly, apply a mixture of 1 cup lemon juice, and ½ cup of salt to remove stains.