In his answer to a question about nail biting, nicorellius referred to not wiping your hands with the "kitchen rag". I've never worked in a professional kitchen, and the only rags I have around my kitchen are dish towels, which I often use to dry my hands.
What exactly is a kitchen rag, and what should it be used for? What should one avoid doing with a kitchen rag that you might use a towel for in a home kitchen?
A kitchen rag is typically a white, rectangular towel that has various duties in a professional kitchen. Some of the uses include: wiping-down counter tops, sopping-up spills, securing cutting boards (use DAMP rags), and grabbing hot pans (use DRY rags).
Generally, it is a good idea to wash your hands with soap and a sink. Often kitchen rags are used to clean debris from the hands between preparing food items.
Usually the rags are dropped-off, picked-up, and washed by an outsourced service provider (e.g. Cintas). The kitchen rags from these providers often have a thin, colored line that runs lengthwise down the towel.
If you would like to find some for your home, try searching 'bar mops'. They are essentially the same as kitchen rags, and are usually very cheap.
A kitchen rag does not, as far as I know, have to be something exclusive to a professional kitchen. In this very old NY Times letter to the editor, the writer talks about a cloth used to wipe the floor as either a file cloth or a kitchen rag.
A kitchen rag is simply a cloth that can be used for many things around the kitchen. You might wipe your counters with one. You might wipe your floors with one (I hope you don't wipe both your counters and floors with the same one). A dish rag would be a similar term that is a name for a wash cloth-ish sized absorbent cloth used for washing dishes. I've heard of a friend's roommate using the same kitchen rag to dry hands, dishes, and sop up liquid from a raw chicken off of the floor - obviously that's an improper use of a single rag, but rags could be used for all those tasks without cross-contamination if you used one for each task.
To sum it up, most uses for a kitchen rag can end up spreading bacteria. If you've got an open sore, you don't want to be doing that.
One logical answer I can think of is in a professional kitchen you move hot handled pans in and out of the oven or on and off the stove protecting you hand with a rag or kitchen towel. From experience I can assure you that if your colleagues decide to use your rag to dry their wet hands then you try to pick up a pan handle that has been in the hot oven with the damp cloth, the resulting burn is very unpleasant! As is the language used afterwards.
