Mistress Alexis did not have time to teach her slave to be competent. He had to find the time to do it by himself and still manage to meet her expectations and timelines. To show him how serious she was, the mistress used her stinky socks to dominate him and he was scared shitless of her and that drove him to change and do things the way she wanted. He taught himself everything he was supposed to know.
Mistress Alexis did not feel like using any of her strength to punish this slave. She wanted to do it in a way that would still be effective without needing the use of any strength from her. So she used her smelly socks to do it. He was made to lick them and she told him he did not have a choice but to do what she wanted. She sat back as he did it.