Increase hair growth.To boost scalp’s productivity, use this mask 2 times a week. Mix 2tbs of mustard powder into 2 tbs of warm water. Add 1 egg yolk and a tbs of any vegetable oil to the mixture. Work the mix into your scalp and cover with a shower cap; leave on until tired of the tingly heat, don’t keep it on for more than an hour. Rinse with water (but keep it out of your eyes). If you didn’t feel any heat the first time, add a tablespoon of sugar to your next batch.