StarDust, I'd say by the comments of the majority of posters in this thread that you should tell your son to concentrate on teaching and not worry so much about the janitors. My guess is most of your sons' fellow teachers would advise him to do the same.
Isn't it always interesting that a poster makes an out of line comment and then fades into oblivion when others challenge it. Maybe she's dusting her fireplace mantle today.