4. White Vinegar. You can also whiten the area underneath your nails using white vinegar. One tablespoon of white vinegar along with a small cup of water, can whiten your nail tips if you just leave your nails soaked in it for 5 minutes.Don’t forget to apply hand and nail cream to keep them moisturised. 5.ou can also whiten the area underneath your nails using white vinegar. One tablespoon of white vinegar along with a small cup of water, can whiten your nail tips if you just leave your nails soaked in it for 5 minutes.