Sounds no more corrosive than the "permanents" my grandma insisted I had done at the local beauty school from ages 5 to 11.
She was a proud Scandahoovian (prolly spelled it wrong) who survived the depression and was convinced my stick straight fine hair was a curse. So she took me to the beauty school because it was cheap, and made me sit in a chair while students applied chemicals to my little head. They all were like "look how grown up you are" while my scalp burned and my eyes watered from the vapors coming off the cotton around my head that was suppose to keep the chemicals from my eyes. My hair was curly in the end, but smelled awful. Then Grandma would forbid me from washing my hair for 3 days "so it can set". After 3 days, I would wash my now greasy curly hair and the curls would start looking funny. A few months later, Grandma is talking about "going to the beauty school for a permanent. You need one too. You get to sit on the chair and feel pretty and grown up!".
She died when I was 14. I miss her so much. I don't miss the "Permanents"
Most black girls I know just use a straight iron and a shitload of conditioner.