I appreciate the OP's post and found it interesting -- I have no doubt there's dirt or germs of various types in all hotel rooms no matter how clean they look to the naked eye. But.... who cares? I figure I get exposed to the same or worse out on the street, in a Starbucks, in an office, on an airplane, etc.

Since I started traveling heavily some years back (weekly flights, 120-180 nights/year in a hotel) I have actually noticed I get sick less frequently and when I do get a mild case of sniffles it seems to be gone within only a handful of days. I can only assume my immune system has gotten stronger from the increased exposure to a variety of environments and germs. I try to remember to wash my hands when leaving a restroom and that's about it, and it works fine for me.