My riding boots are really dirty - and I know this slave thinks licking dirty boots is extremely disgusting. But of course I've my ways to ensure the job gets done anyway. I order him to put his hands on the ground and then start to trample his hands under the hard soles of my riding boots. Then I order him to start cleaning the boots with his tongue - while I still stand on his hands. Of course, the slave now knows the pain is going to be much more intense if he doesn't do his job properly and starts to lick away all the dirt! But the sadist in me can't help it - I've to trample his hands some more even if he does a good tongue-cleaning :-D