Made some modifications - 10x 100uf 450V capacitor in series parallel for 500uF 600V. Switching from -12V with ripple noise to add a sound effect and timer to allow charging via voltage doubler to 600V.
New down and dirty working circuit, voltage doubler for 600V, delay hold -12V before discharging capacitors, relay isolating inverter eliminates the need for series resistor giving a faster charge and no heat.
Some time ago I saw a miniature fog machine (intended for costumes or similar applications). It was the size of a pack of cigarettes and used a LiIon battery. The tank was a 5cm³ medical syringe with the plunger removed , instead there was a small rubber plug and the heater was a piece of the thin stainless capillary tubes which are used to make hypodermic needles. This was heated electrically and a tiny pump pressed the glycol/glycerol smoke fluid through the capillary tube.
This worked very nice, the only drawback was it's pricetag, around €700 to 1000,- I think the device was Swiss made.