Hopefully the custodial staff will now get around to cleaning the doorknobs in my BU building. Clean floors are nice but I usually don't touch the floor. There is a buildup of dirt stuck to many doorknobs including the bathroom that has been there since the cows came home. I peeled it off my office doorknob with a razor and a stiff brush. It is a nice substrate for growing things especially when it gets moist from people's washed hands when they leave the bathroom. Yuck.