Washing up liquid is corrosive. Never use it on a plane.
I wouldn't use it on a plane because the cast iron body might rust and the cutting edge of the blade might be blunted. But then, I've never noticed any flies or bugs on it.
I
do use a tiny amount of it in the water bottle to break the surface tension when using it on the aircraft canopy. At this time of year, it needs cleaning after every sector, sometimes four or five times a day.
Recommended for canopies by the chief engineer of a big helicopter company I used to work for. Been using it for years on aircraft canopies with no problems.
Mind you, he also said use nothing harder than a pilot's soft hand to wipe the bugs away to avoid scratching the plexiglass. I showed him my knarled old DIYer's hands (mine were far rougher than his) and he said "For Christ's sake, get yourself a chamois leather"!
We're not talking about using enough to work up a load of lather here. As I said, just a drop in the water does the trick. The aircraft gets washed, waxed and dried off by the professional cleaners about twice a week.
How corrosive are insect remains, in any case? I'll bet they're a lot worse than a drop of Fairy liquid.