Brush dried-stain material off the surface of your Timberland boots with a dry, natural-bristle scrub brush.
Sprinkle talcum powder over grease stains until they are completely covered. Leave the powder on your boots for 20 minutes. Brush off the powder off using a dry scrub brush.
Fill a bowl to the halfway point with full-strength white vinegar. Dip an old toothbrush in the vinegar to dampen it.
Moisten the stain with the toothbrush. Scrub the stains gently with the toothbrush and white vinegar. Blot the stain with a clean cloth. Repeat this process until the entire stain is gone.
Air-dry your Timberland boots. Blend the nubuck by brushing it with a brush designed for suede.