If its a professional porn movie i believe the toys are used on only one girl to prevent the spread of any std's, yeast infections, virus's, and the like. Which is weird if you think about it because these chicks go tongue deep in pussy and ass. I may be wrong but I swear i had heard the question come up one night on love line years ago and they had porn stars on who answered. Or maybe it was night calls on the playboy channel, i dont remember where i heard it. Its like an industry starndard though as i undederstood it.