For mist washing, you begin by filling your vessel about half full of the  WVO/VO to be washed.  A fine mist of water is then gently sprayed over the VO surface. You should use plant-misting nozzles designed to generate a very fine mist. Spray the mist over the top of the WVO/VO  in such a way that you don’t break the surface of the oil. If you break the surface of the oil it may form an emulsion. In most cases warming the VO/WVO and water to 90-110 °F will improve the effectiveness of mist washing and lower the amount of water which is required.

Since VO has a lower specific gravity than water, the water will sink to the bottom and the VO will remain on top of the water.

Turn on the spray and adjust the flow so that you’re not using too much water too fast. You don’t want water to pour in. As the droplets of water hit the surface they will slowly sink, passing through the VO taking with it any water soluble contaminant and most particulates as well.

In your first round of washing, the water will very dirty and probably smell like any water soluble contaminants it has picked up. It will collect in the bottom where you can drain it out after a few gallons have collected. Methods for continuous mist washing have also been developed where the water is automatically drained as more is added.

Basically, run the spray until you determine that water soluble contaminants have been completely  removed. . The amount of water you use for each wash will be determined by this as by that time the majority of solid/particulate contaminants which CAN be removed by mist washing WILL have been removed as well.

Amounts of water needed run from  a couple of gallons  all the way up to an amount equal to 50% of the batch. Drain the water often. Repeat the mist wash until the water you drain is clear. This should amount to just a couple washes. After the final draining of the water, let the washed VO/WVO sit for 12 hours so any remaining free water will have a chance to settle to the bottom. Drain any remnant water from the bottom.

Let the VO  cool to under 90°F and filter it through a 10-micron filter while cold. Then dewater using either heat/settling or vacuum dewatering techniques.