Looks good to me. Was thinking along the same design lines but would have to round up a high pressure pump and mist heads. Another way might be to use an aerosol head and compressor. An ordinary asthma nebulizer puts out a fine smoke like mist or can take the top off for larger particles. Doubt if the compressor is rated continous duty but a 10-25% duty cycle might work fine. Controling the noise might be the hard part. I`m still thinkin on how to proceed or just let well enought alone. The dirts doing just fiine. let us know how your setup is working out.