My hiking boots are totally muddy after a nice long walk in the woods - and I didn't clean them yet. I walk up to my slave holding the boots in my hands. I then put a first one on - and put my foot on his face while I tie the shoe. After putting on the second shoe as well I get on his naked chest and clean my boots on his skin. I also step on his head and use his face as a doormat for my muddy boots as well. In the end his chest and face are completely covered in mud - and my boots are more or less clean ;-)