J.K.
I have not seen that commercial yet, but I am definately not scared of that word (I taught several years of health education that included teaching sex education to adolescents, so using proper terminolgy was important w/out looking too embarrassed.)
So you guessed it. My children already know correct terminology of their parts at ages 3 and 4. I still get a kick out of it when my 4 yr old asks me, "I forget, Mommy. You have a ba-gina, right?"