Ultrasonic home humidifiers seem like a practical idea for rooting cuttings. The operative word being "seem". They are relatively cheap, and can serve multiple uses, and would be easier to set up than other mist systems.
The mist they produce is cool, the micro droplets do not fall to the ground, or accumulate into larger drops. These units are very successful at getting water into the air, and may provide what is needed for mist propagation very inexpensively.
My other thought is... If you filled a home ultrasonic humidifier with "willow water", would the rooting hormones found in the micro droplets increase the rooting/vigor of cuttings?.
Anyone tried anything like this?
Hardiness Zone 6a