Yes exactly! You sound like Dave; we tried the hand pressure tank and a compressor. The real problem was the nozzle which would be very sensitive to pressure. If the pressure was just a tiny bit off it either would not spray or blow the seals.
He thought of the swinging arm and had it mounted on a track that was timed to rotate in an arc. The track was too brittle though; he used PVC and it kept splitting. And the spray had a very short range as you can geuss; it had to be within about 8/10 inches from the target.
Rube Goldberg; but the thing is it really did keep you cool when it worked; and the mist was so fine that it would evaporate on contact and you never really got wet.
The small tank Idea was good because this used so little water per hour that a one gallon tank lasted half a day.
For a long time he was unemployed by choice and I got so much shit done on my house. Sadly he has returned to work. And married. Bad news.
He has a scheme to buy 52 timeshares then move out of his house.Also; I don't have another example.