This guy used toilet bowl cleaner and it left the concrete lighter than the rest! Who do I believe?!
This guy used a quart of Goof Off and said he probably should have used two, but it got most of his big stain:
https://youtu.be/7ISXk0a5eAU
This guy tried Zep and muriatic acid--he said he already used a pressure washer!
He used a full chemical-resistant suit and respirator and kept saying that the muriatic acid will do horrible things to you if you don't protect yourself.
It seemed to work completely, but he didn't let it dry before ending the video!
This redneck said he spent hours the day before cleaning an old stain he just made and then today he tried gasoline and overpriced kitty litter.
He was outside, but he used a lot of gasoline!
I still worry about the fumes!
If you think that is bad, he then used a torch next to the house!