I do a lot of hobby car work in my carport, esp. on older cars, which means an accumulation of really nasty oil and grease stains of various kinds. Using typical cleaning products to try to clean this up generally doesn't work all that well, and tends instead to spread the oil and grease, and their stains, without really looking like you've done much to remove them.This stuff is different. First of all, it takes way less time than trying to clean concrete with other common cleaners. You also end up a lot less dirty at the end—there's no splashing, no treading in greasy liquids, etc. There's basically just light-colored powder that's easy to brush off of anything it gets on.Most importantly, it has done a better job of actually cleaning the dark, grimy-looking staining out of the concrete than anything else I've tried so far, and the best part is that there's no mess and no oil and detergent being sprayed off into the lawn or into the drain system. Instead, you just sweep it up. It seems to stay powder-like and light in color, even after having been used on fairly thick and viscous layers of grease. It sort of just magically digests them away.One key point that I've learned as I've used it over the last few weeks—you don't want to just sprinkle it on and then leave it there. I did that for the first couple of weeks and didn't notice much of a difference. Things really took off when I began *sweeping it around* every day. Just about 30 seconds each time with a broom across my entire carport floor. Back, forth, here, there, just manipulate it enough so that this stuff gets all rearranged on the surface.Once I did that, it was only about a week before most of the staining was entirely gone and the concrete is about 10 shades brighter than it used to be. Then, once you're satisfied with where you are, you can just sweep it all up.I have no idea if this can be reused, but it's still in dry powder form after having taken a 1/8" layer of junk off the floor in some places, so I've saved it in a coffee can and we'll see what happens when I have more stains I need to clean up.