PP Candy (PPキャンディー) (Sweetrots in the manga) is a "vitamin" made by Bulma.
Bulma used the PP Candy to make Oolong obedient. She tricks him into eating it, but after he eats it, any time she yells "Piii Piii!", he would have cramps and "the runs". In other dubs, she yells "Piggy!" and in the manga she whistles "Swee!"