Removing stains on floor tile grout
I am having a terrible time removing stains from grout that was here when we bought the house. It is in the kitchen and I have tried everything under the sun. Some one said vinegar and that didn't work. Ive also tried oxyclen and it didn't work either. I have tried clorox clean up and awesome. We are in the procees of selling and I really wish I could find the right thing to work. Someone said muriatic acid with 50% water but that sounds leary to me. Please help!:)