Mealy bugs that you can visually see can be killed on contact with a small wet brush (eg a artists paint brush) dipped with rubbing alcohol...however as Llyod said, do isolate the infected plants. Mealys can be amywhere on the plant, planter, cup etc. the male mealys do fly and can infect other plants nearby... Do consider replanting the plant in the spring and maybe douse it wilth neem seed bath and some low concentration of dawn dishwater... This might be repeated until you see no more mealy bugs.