Slave Coerced To Lick Extremely Dirty Shoes

After a few long runs my trailrunning shoes collected a lot of the dirt - and the slave will now be coerced to clean them with his tongue! I sit down on the cupboard and order him to start licking the disgusting mess from the shoe soles. With the dry dirt its quite hard for him to get it all out of the tread - but then hell simply have to lick them longer! His tongue is getting dirty and hes close to puking - but I dont care and just humiliate him even more! Lets see how clean hell get them! And if he doesnt clean them to my satisfaction, Ill use his stupid face as a doormat - and he surely doesnt want this to happen with these shoes!