First, clean the whole chamber and top Plexiglas disc in warm, very soapy (household dish washing soap) water with a clean, fresh sponge. This will help dissolve the mineral oil coating from the spraying of the droplets into the chamber. Rinse in clean, warm to hot water.
Rinse again with distilled or deionized water to remove any film residue.
To clean the optics use Windex and a cotton swab and very gently swirl the cotton swab on the flat optical window of the chamber. Then repeat this process on the lens that focusses the light source. Make sure to clean both sides of the lens.
Next dip the cotton swab in the deionized or distilled water and swirl the q tip on the window and lens.
To clean the brass plates, wet a paper towel with isopropyl alcohol or denatured alcohol and wipe over the entire surface of the plates several times to remove the oil residue.
Next, take a tissue (Kimwipe, paper towel, not toilet paper, too weak.) spindle the corner of the paper towel so it will just go through the hole in the top brass plate and poke out the opposite side. Dip in alcohol and spin the “pointy” part of the spindled paper towel thru the hole cleaning out the oil residue.
For the brass base plate, wipe with a paper towel soaked in alcohol, then wipe with a paper towel dipped in deionized or distilled water for a clean conductive surface.
Dry all the components with a gentle stream of compressed air.