I am ready to be shot down in flames here and perhaps it's just the excesses of Christmas coupled with all of the war films that have been on but here we go.
If Joe and Joanne Public don't know what "CLEAR PROP" means, and it's them we're trying to save from sticking any extremity into the whirling disc(s), then what would be wrong with shouting something that they might have a clue about?
There's ozplanes "F..k off you dozy b.....D" which I think is quite to the point but may not be ideal in all situations, there's always Avgas172's "getoutadebloodyway" for more of a family audience and, of course, the fledgling's "CLEAR" which is, well, quite clear.
I was just wondering about shouting "CONTACT" - yes, I know that it has a specific meaning and you'd feel like a right sad tw@t shouting it out the window of your 150 but the point is that everyone's seen the films, everyone knows that when someone with a moustache shouts "CONTACT" the quiet bits get loud and the still bits start to move. So, might it help to stop someone being injured?
Now, if you could all please stop laughing for long enough to type "Shut Up, JAFO" then I'll get my coat.