Wash it with some scent killer soap. Air dry it outdoors. When it dries spray down to the point it's wet with some scent killer. Double check that rubbemaid container you store it in. Many times they can stink worse than anything. Plastics do give off an odor. Some more than others. If you're using a prusic rope or something that could be your stink too if it's new. I didn't see your last post before I posted this. From what you describe, I bet it's the container.
This is a container I have used for a couple years. It looks like the camo pattern on the vest is silk screened onto the fabric. I am 100% certain that this is what is causeing the odor. It is only the vest part that smells. None of straps or buckles have an odor that I can detect.
For those suggesting that I soak it for a couple days. I first soaked it in Atsko sortwash and water then threw it in the dryer. This did nothing to get rid of the smell. I then soaked it in dead down wind for a couple days and then hung it on my back porch. Didn't seem to do much to eliminate the odor either.