I used my silicon grip for a while and although it works 100%, is has a flaw. As soon as some fluid gets between the airbrush and the silicon, it starts rotating. So I decided to try it again.
I made my “rail grip” ala Mike Learn style. It was just hot glue that I build up until desired shape and then sanded it down more. But first I covered the area where the glue was gonna be with cling wrap so that the glue does not stick to the gun. It did not work as the glue melted the cling wrap, DUH! I then smeared some of the water soluble bath oil that I use to lube the airbrush over the area and stacked the clue on top of that. Worked perfectly. You just need to wash the gun and the inside of the grip properly otherwise the grip slides around.