"Wash your hands before and after using the toilet"
I have heard that SOME restaurant workers do the "after" part, SOMETIMES, also!
I'm no restaurant worker, nor have I ever worked as a researcher; yet I follow that practice anyways. My mother taught me at the same time that I was pottie training, and old habits die hard.
I see signs in convenience store restrooms stating "Employees must wash hands" and I always want to take a marker and add; "We hope that the rest of you do, also."