How to remove mat stains?

I’ve seen a few cases where the front door mat has stained the surface underneath. Just wondering what chemical is used to remove it?

Usually if it’s the mats with the rubber type underneath I will take a small amount of degreaser on a brush and agitate it. Then rinse low pressure, might have to agitate another time but that usually cleans them up.



I run my SC over it and rinse. I put mat back after I’ve washed it off. Have never had a complaint in 1000’s of housewashes and have never had a homeowner even ask if I could get a mat stain off.