Dandruff is good for you.  Once every winter, in colder climates, you gotta let those little bugs chew you a new scalp. 

Mattress mites help your skin by eating yeast and other nasties.

Every time you hold in a sneeze three minutes of your life in a nursing home is lost.

Never swallow your own spit.  Try not to swallow others.

Avoid substandard orgasms.

Besides, we now know Blue Balls is good exercise.*

Biting your nails boosts the immune system

A filthy baby is a healthy baby.

There are three main sources of human suffering:

• Lack
• Excess
• Boring moderation

And we can fix that.

*pervertedwisdom does not condone the deliberate self-infliction of blue balls by athletes prior to competitions as a method of boosting testosterone and enhancing performance.