Why can't you do a bleach and redye?

Other options are baking soda paste, pH level of about 8 or 9, or an ammonia solution with a pH level of 11 or 12 (I advise against this, I tried the other day and had a terrible, terrible throat for the next 2 days it was DISGUSTING and nearly made me throw up)

Anything highly alkaline is supposed to open the cuticle, and heat is also supposed to help. What length is your hair and what are your smoking habits? Also what country are you in?