Okay, so the phrase makes no sense, but having tried to say it 10 times fast, we'll confirm that it's quite a doozy. We haven't sprayed so much spit since our last time at the dentist.
“If anyone can say this [phrase] ten times quickly, they get a prize,” says Stefanie Shattuck-Hufnagel, a psychologist from MIT who helped create the verbal puzzle.
Shattuck-Hufnagel (now there's a tongue twister) says that the "pad kid" phrase was so difficult, test subjects "either couldn’t repeat it, or simply stopped trying altogether." The good news is that you'll probably never, ever have this phrase come up in conversation. (Boston Magazine)