Parts list and costs:
Neon Transformer, 5KV to 7KV $45.00 from a repair store for signs
1 square foot of window glass $5
2 square feet of stainless steel mesh $16.00 or copper mesh $3.00, divided
5 gallon bucket
less than 80CFM fan $5
Solder mesh to output of neon transformer.
Hot Glue mesh to glass, leaving a TINY space between glass and mesh. leave a 2" ring of glass around the mesh (in other words, dont cut the mesh as big as the glass, make it smaller)
Plug in and test (DON'T for God's sake touch anything that is plugged in!!) If there is a light hum and blue glow from it, you are good to go. If you get a yellow or white arc, then you are arcing and need to isolate that section.
Now to make a fan powered unit for forcing it around, place the generator in a 5 gallon bucket, tape the top off and secure everything so it doesn't shift around.
Cut a hole for exhaust and one that is the size of your small computer fan or desk fan.
It is very important you don't make the fan run too fast. 80 CFM is barely a breeze felt on your hand. Think about a CPU fan on your PC. That's about right. If the air flow is too fast, it introduces Nitrogen Oxides into the air!
That's my plan, it works great. I'll get photos if I remember when I'm out at the boat next time. Run it for no more than 2 hours every few weeks for a good mildew and smell control. It even killed the smoke smell from my brother when he was aboard!
Stainless mesh lasts longer; you shouldn't have to worry about it breaking down after a few months of use. Watch it for arcing - if the glass is too thin (the mesh panels are too close together) it actually fries holes right through the glass. That's why I said look for colors, because they are the first indication you have an arc... well that and the sound. You should get a nice hum not a buzz.