smells of bikes on Nostr: I've messed a bit with this, and yes, long stem on the nozzle just like WD40 cans ...

I've messed a bit with this, and yes, long stem on the nozzle just like WD40 cans seems to be able to get the spray outside the area where the rotor airflow is the worst. Other people have talked about using enclosed rotors, but you could make an interesting quadcopter that's really long, two rotors on either end and a half meter between them where there's no real airflow from the rotors.
A BIG one with something hanging down could do dot-matrix printing in a hurry.