Home remedies or ways to get rid of hard nicotine stains on fingertip ( just 1 fingertip ) but it's super dark and noticeable end embarrassing in public tried bleach , toothpaste, rubbing alcohol?

Use a nail file, pumice stone, body brush, salt scrub, or sugar scrub to sand away some of the nicotine stains on your fingers.[1] Use gentle pressure to rub the grit onto the yellowed area of your fingers just until the stain looks faded.do not rub excessively or you may cause bleeding

If your finger-tip is damaged, think what your thumb lungs look like. You could quit smoking and allow your lungs to heal as the stain gradually disappears from your finger-tip. Your GP has many ways to help you self-heal.