The dark spots here is power steering fluid. Many years old. I know with cold water it won’t ever come out and may only lighten up a shade at best. Without getting $60 a gallon industrial degreaser, is there anything you would recommend maybe half that cost or less? This is my driveway so it’s for practice. Already did the normal mold and mildew pressure cleaning of it. Certain parts were so bad that they only came clean in the post treatment, not in the pre treat or wash.
There once was this thread:
But the one I had recently may also be of use, even though my issue was an oil-based wood stain…
Mine has wood stain drops and pressure cleaning does nothing on the patio furniture or concrete. I think you need another method combined with chemical to kill that. If they are not calling you exclusively to kill that then best to tell them its beyond garden variety pressure cleaning so there is no expectations. Im sure people better than me can do it.
Take powered laundry detergent make a paste. Leave overnight surface clean. I can’t guarantee it but it has worked in my own shop
What is “powered laundry detergent” compared to any other garden variety detergent? Nice thing is it’s not part of regular pressure cleaning and can be an up sell with no guarantee.
I can’t really give you a honest answer about the difference. The powder is easy to make a paste. You could try just regular detergent
You had two people give you three recommendations. Try 1, 2 or all 3 and see if one of them works.