here's what I've heard.

Down by the banks of the hanky pank
where the bullfrogs jump from bank 2 bank
singin' eeps ipes opes oops chilly willy ding dong
I pledge allegience to the flag
Michael Jackson makes me gag
Coca Cola has caffeine
Now we're talkin' Billy Jean
Billy Jean is out of sight
now we're talking DYNA-MITE!

I haven't done it for a while, but there's a longer version that says something about "kissed my boyfriend behind a magazine... hey girls, wanna have some fun? here come the boys with their pants undone"

Yes, these were actually sung by young children (1st-5th grade). not that many of them understood what they were saying...