Failure Is Not An Option
T  h  i  n  k    hard,  work
Although Ronald Reagan originally spoke those words publicly, personal hygiene is personal.   So personal, in fact, that one royal personnage was inspired to say about a related issue: "Horses sweat, men perspire, and ladies feel the heat."   Still, no consideration of health could possibly be adequate without consideration of this very important area.   Even animals are known to have personal hygiene, with birds preening feathers, cats grooming their fur, and raccoons washing their food before they eat it.   So, what makes cleanliness so important?
In the bird's case, healthy feathers are essential, a matter of life and death where feathers are relied upon for aerial guidance and insulation.   The other two cases are perhaps not as easy to grasp.   Clearly, these animals know instinctively what they must do to survive, and part of that is prevention of infection, because in nature microbial lifeforms abound.   The microscopic bacteria in your mouth, for example, if not tended to with regular oral hygiene, cause plaque buildup on teeth and eventually cause gum disease and loss of teeth.   While this takes a seemingly long time, other diseases spread by microbial infection are not so slow.   The common cold, as well as many related illnesses, are believed to be easily passed from person to person by handshaking, the moist palm of a hand being an environment particularly well-suited to this strain of virus.   While washing the hands frequently may help allay the spead of disease, some compulsive behaviours have been documented which report the washing of hands some 200 times in a single day.   On the other hand, keeping a personal written record can facilitate the regular brushing and flossing of teeth, and serves as a reminder that this should be done twice a day.
Regular showers or baths, you may have noticed, can make a noticeable improvement in the way a person feels.   Notwithstanding this, many soaps can cause irritation or allergic reaction if used too much, so substitutes may be searched for, and washing should anytime be restricted to only those areas that specifically need it.   Fix it before it breaks, but if it ain't broke don't fix it.   The true test of anything is that it works, so if it's not working for you, try something else.   However, certain general recommendations apply, like the need to wash hands after the process of elimination.   Certain organisms may find a happy home in one bodily orifice, but they were not intended to be taking up residence elsewhere.   The consequence is real, and it is called disease.   For example, urinary tract infections are caused by contamination of the urinary tract orifice.
The Bible, under the Law of Moses, commanded that the elimination of body wastes be outside the camp (Deuteronomy 23:10-14), the reason being God's potential displeasure at seeing something indecent in the camp.   The spread of disease is correspondingly rampant in countries which lack proper sewage disposal, whereas centuries ago Jehovah had said to bury the waste in the ground (Deuteronomy 23:13).   So wise is the Bible in matters of hygiene, that the modern medical method of quarantining patients for 14 days is still same method used by the Israelites under God's Law about three thousand years ago.   Note that in the Bible, the period of quarantine for leprosy was 7 days followed by another 7 days, or 14 days (Leviticus 13:4,5 "But if the blotch is white in the skin of his flesh and its appearance is not deeper than the skin and its hair has not turned white, the priest must then quarantine the plague seven days.   And the priest must look at him on the seventh day, and if in the way it looks the plague has stopped, the plague has not spread in the skin, the priest must also quarantine him another seven days").
When the Israelites were wandering in the wilderness, they were prohibited from eating certain animals such as carrion-eating birds (Leviticus 11:13; Deuteronomy 14:12), which were considered unclean (in other words, disease-causing).   Today, even with modern refrigerators, people are careful in preparation of various foods because of the increased health risk associated with these.   Pork, poultry, and even bear meat pose specific health risks such as salmonella, campilobacter, or trichinosis when not cooked thoroughly.   The list is not intended to be all-inclusive, but it just goes to emphasize the necessity of good hygiene.
Thus personal hygiene is a preventive measure that has served even animals for thousands of years.   In the words of comedian Paul Rodriguez, failure may not be an option, but it's a definite possibility.