0
Usually a test tube brush is used or if it is small, a pipe cleaner.
A test tube brush is a long thin brush with an extended handle. It is made for cleaning the thin tubes.
it is made drinkable by people trying not to pee in there and by cleaning it with a filter tube.
You should use a test brush and a cleaning substance.
Rotating the body tube allows you access to other parts of the microscope that may need cleaning/repairing.