There is no set amount required per regulations. Cleaning of the aircraft is entirely up to the operator, but if an aircraft operates in corrosive conditions they will typically be washed more to help lengthen the life of the aircraft.
yes
High pressure wash equipment
Models wash their hair often, depending on the work they do.
Do not wash... They absorb water...
The usual term for that is prop wash.
High Pressure Wash Equipment
Not often enough.
Prop wash is caused by a passing propeller driven aircraft. The spinning prop creates a vortex like wind that can be quite violent.
Cats wash themselves very often. A Cheetah would definitely was after a kill or after eating.
Women should wash their hair at least every two days. But I wash my hair everyday.
It is recommended to wash a towel used for bathing after every use...
How often you should wash your hair in a cold climate depends on your hair's natural greasiness and how comfortable you are with it. You should wash it whenever you feel like it is too greasy.