Madame Marissa is not a one trick pony when it comes to slave punishment and slave humiliation. When she is mad at a slave, she usually does what she feel like at that moment. Today she was disgusted at her slave and she wanted to make him experience that disgust. So she spat on the soles of her boots and she forced her slave to lick the spat on dirty soles till they were clean.
Mistress Ava Black and her friend are into spit fetish. And since they do not have large amounts of saliva to spit out every time, they found a concoction which helps them to secrete more saliva. They like to take the concoction whenever they want to humiliate a slave using spit. They take it and then when they start getting more saliva, they make the slaves drink or lick the saliva.