I did my last relaxer with Affirm regular and I didn't smooth my hair because I only left it in for 13 minutes just like it is written on the relaxer tub. I think I have resistant 4a/b hair and now I have waves in my hair. My question is, can I leave the relaxer longer than 13 minutes and smoothing it? How long is the maximum time you can leave the regular relaxer in? I want my hair to be straighter but not bone straight. Anyone can help me?