AHH yes, I have red death clay , caliche and Marl (love that word) all within 30 ' of each other. I do not get a great deal of precipitation so the times of gunk or numbered. BUT when they are here, my husband is always on me for my shleppy oblivious ways of entering the home. Yes , I do have a sharp edge on some metal C channel on the porch that O use for the first swipe. . I am often let the shoes dry a tad and hit the shoe with a steel brush that my husband uses to clean lumber with before he machines it. He probably wonders how all those pebbles and clay get in that brush. I have been thinking of embedding that old hoe (whose handle rotten away) in a sunken pool of cement with the blade sticking appropriately up , But I would probably end up tripping over it and splitting my knee open. I am still thinking.

We bought one of those heavy rubber shoe cleaners at Tractor Supply years ago and it's our favorite. It is always on the back porch and it cleans our shoes pretty well. I whack it on a tree when it's dry to clean it.

As a child I lived in the country. We always had a boot scraper mounted into the concrete. It was a flat blade that stood about 4 inches about the concrete. I have seen some that now have brushes mounted on both sides for removing the mud from the sides of the boots but we only use our knifes to remove what was left. This was always on the side away from the door way so no one would trip over it. We also took off our boots and left them in what they call a mud room now. We did not have fancy names back them only reasons for why we did what we did. A nice comfortable pare of shoes were always inside or we had those slip-on boots they sold back then.