To reiterate, with respect to the episode title, "Charm School" is a Russian program where Russian children were adopted by American families, so that these children can grow up and infiltrate the highest ranks of government in order to disseminate sensitive information , or influence (destabilize) the country.
Moskali is a Ukrainian term which literally means someone from Moscow. The revised definition has more derogatory connotations, especially since the Russian incursion in Crimea, which was Ukrainian territory and the conflict in East Ukraine.
DNI is short for Director of National Intelligence.
Det cord is short for Detonation Cord.
Charcoal, is essentially burnt wood. Once Bryan observed that the campaign manager was poisoned, he grounded the burnt wood, mixed it with a liquid, in order to administer an charcoal or gastric lavage, so that it could bind with the toxins.