Carpet Stains Gone
With GreaseMaster diluted at 100:1, I sprayed it on and gave it some time to soak into the fibers. I came back after about 5-10 minutes and gave it a quick spray to reactivate the solution, and scrubbed the mat with a clean floor brush. The stains came right out (the dark and somewhat dirty appearance of the carpets was strictly due to a lighting problem I couldn't correct for and wasn't actually there in person).
I followed up with a dry rag to help remove the excess GreaseMaster, but let it dry without rinsing the mat because I have found that by leaving GreaseMaster on, dirt build up occurs at a much slower rate and (as I've mentioned before), once dry I can't tell it's on there. Click image to enlarge.