Fill with water
and what?? Cook it
That's a new one... Stick it out in the sun with all the vents open, that should allow any left over fumes to ventilate out. I did mine recently by the same method. I also used my air hose to blow probably about 40gals of air thru it. Bead blasted it clean on the outside, then PC'ed it. Came out fantastic. If you are going to treat the inside of the tank with some sort of protective coating, (which I personally dont really recommend, it has a way of finding itself into the fuel system) Do this after you PC it. Good luck. My tank sits inside my car on the trunk floor and will look new for 5 lifetimes!
