To remove mehenthi, you can try the following simple steps:
You can apply bleach on your hands, and allow it to dry completely and then rub your hands for few minutes to get rid off , which will result in fading of the color of the mehndi well.
You can try to remove mehendi by dipping your hands in the warm water for few minutes and then rub hands to get rid off.
You can take bath in a pool where chlorine is added which will help you to fade mehenthi quick. You can try this in your home also by taking vessel containing water and adding chlorine and then dipping your hands in it. Don't follow this if you feel skin irritation.
Frequent wash of hands for more than 10 times in a day will result to great extent.
You can apply toothpaste on the mehendi and allow to dry, then rub the hands to diminish the colour of mehenthi.
Use paste called baking soda which is mixed with lemon. Apply this paste on your hand in order to fade the mehendi. But this can make damage to your skin. So apply very little paste and wash it thoroughly after drying.
For best practice, use your hair conditioner when taking bath.
Try with olive oil. Put few drops on your hand and gently rub your hands to fade colour of mehenthi.
Hope this will help you!