Who leaves a relaxer on for 18-25 mins?
Nobody really needs a coarse or super relaxer. It's too strong. You can use the regular and leave it on a little longer and get the same results. I'd rather be safe than sorry.
When I was a child my mom and I went to a hairdresser and she decided to be cheap and just buy super relaxer and use it on everybody's hair. My mother had to get her shoulder length hair cut into the Halle Berry cut it was so damaged. I only suffered damage on one side and it grew back quickly. I will never let anybody near my head with a strong (or even regular strength relaxer) again.