I had always had good prop discipline instilled into me from a young age. Imagine my surprise and apprehension when I was told that the islander needed a comp wash once a week.
The instruction was to spray water into the intake, whilst balancing one of the prop blades on one's shoulder. This was to take up the strain of the prop as the captain then repeatedly spooled the starter motor for 3-4 second bursts.
Most dangerous thing I ever saw, and also completely pointless. The spray was just a 5l hozelock container with tap water in it.
I raised my concerns to the higher ups, and was told that we HAD to do it or the engines' warranty would not be upheld.
Nonsense!