A reader asked Katie Fairbank of the Dallas Morning News, "Why do restaurants use those filthy rags to clean off your table

Fairbank says there have been plenty of times that I’ve watched a disgusted lunch companion wipe down a table right after it was swiped clean with a sopping wet dish towel.

"I am one of those people," said restaurant legend Gene Street. "I carry my little thing with Clorox wipes around in my car. When I go into a restaurant, I wipe it all down – especially the salt and pepper, since everyone touches their nose or their mouth and then touches them. Can you imagine what could be on those?"

The state and cities have regulations on exactly what restaurants need to do to clean tables. If that rag really is "filthy," the restaurant is not up to code, and the inspectors would like to know about it.

"There are a lot of viruses out there that can be transmitted from a surface," said Chauncy Williams, sanitarian supervisor for the city of Dallas. "Bacteria tend not to live long, but there are instances where a wet surface can help sustain it."

Dallas regulations require restaurants to have wiping cloths available to clean work areas, equipment, counters and customer tables. The cloths are always soaking wet, because they must be stored in a sanitizing solution. The solution itself must be tested periodically throughout the day to make sure it’s the right concentration. If it’s too strong, it could be too toxic. Too weak, and it doesn’t do the job.

Cafes, bars, restaurants and fast-food joints are also supposed to change the solution several times each day to make sure it hasn’t gotten dirty.